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2020-04-22Merge branch 'js/mingw-isilon-nfs'Libravatar Junio C Hamano1-2/+15
* js/mingw-isilon-nfs: mingw: cope with the Isilon network file system
2020-04-22Merge branch 'js/mingw-fixes'Libravatar Junio C Hamano1-4/+41
Misc fixes for Windows. * js/mingw-fixes: mingw: help debugging by optionally executing bash with strace mingw: do not treat `COM0` as a reserved file name mingw: use modern strftime implementation if possible
2020-04-10mingw: cope with the Isilon network file systemLibravatar Nathan Sanders1-2/+15
On certain network filesystems (currently encountered with Isilon, but in theory more network storage solutions could be causing the same issue), when the directory in question is missing, `raceproof_create_file()` fails with an `ERROR_INVALID_PARAMETER` instead of an `ERROR_PATH_NOT_FOUND`. Since it is highly unlikely that we produce such an error by mistake (the parameters we pass are fairly benign), we can be relatively certain that the directory is missing in this instance. So let's just translate that error automagically. This fixes https://github.com/git-for-windows/git/issues/1345. Signed-off-by: Nathan Sanders <spekbukkem@gmail.com> Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-10mingw: help debugging by optionally executing bash with straceLibravatar Johannes Schindelin1-0/+26
MSYS2's strace facility is very useful for debugging... With this patch, the bash will be executed through strace if the environment variable GIT_STRACE_COMMANDS is set, which comes in real handy when investigating issues in the test suite. Also support passing a path to a log file via GIT_STRACE_COMMANDS to force Git to call strace.exe with the `-o <path>` argument, i.e. to log into a file rather than print the log directly. That comes in handy when the output would otherwise misinterpreted by a calling process as part of Git's output. Note: the values "1", "yes" or "true" are *not* specifying paths, but tell Git to let strace.exe log directly to the console. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-08mingw: do not treat `COM0` as a reserved file nameLibravatar Johannes Schindelin1-3/+5
In 4dc42c6c186 (mingw: refuse paths containing reserved names, 2019-12-21), we started disallowing file names that are reserved, e.g. `NUL`, `CONOUT$`, etc. This included `COM<n>` where `<n>` is a digit. Unfortunately, this includes `COM0` but only `COM1`, ..., `COM9` are reserved, according to the official documentation, `COM0` is mentioned in the "NT Namespaces" section but it is explicitly _omitted_ from the list of reserved names: https://docs.microsoft.com/en-us/windows/win32/fileio/naming-a-file#naming-conventions Tests corroborate this: it is totally possible to write a file called `com0.c` on Windows 10, but not `com1.c`. So let's tighten the code to disallow only the reserved `COM<n>` file names, but to allow `COM0` again. This fixes https://github.com/git-for-windows/git/issues/2470. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-08mingw: use modern strftime implementation if possibleLibravatar Matthias Aßhauer1-1/+10
Microsoft introduced a new "Universal C Runtime Library" (UCRT) with Visual Studio 2015. The UCRT comes with a new strftime() implementation that supports more date formats. We link git against the older "Microsoft Visual C Runtime Library" (MSVCRT), so to use the UCRT strftime() we need to load it from ucrtbase.dll using DECLARE_PROC_ADDR()/INIT_PROC_ADDR(). Most supported Windows systems should have recieved the UCRT via Windows update, but in some cases only MSVCRT might be available. In that case we fall back to using that implementation. With this change, it is possible to use e.g. the `%g` and `%V` date format specifiers, e.g. git show -s --format=%cd --date=format:‘%g.%V’ HEAD Without this change, the user would see this error message on Windows: fatal: invalid strftime format: '‘%g.%V’' This fixes https://github.com/git-for-windows/git/issues/2495 Signed-off-by: Matthias Aßhauer <mha1993@live.de> Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-03-27run-command: trigger PATH lookup properly on CygwinLibravatar Andras Kucsma1-0/+11
On Cygwin, the codepath for POSIX-like systems is taken in run-command.c::start_command(). The prepare_cmd() helper function is called to decide if the command needs to be looked up in the PATH. The logic there is to do the PATH-lookup if and only if it does not have any slash '/' in it. If this test passes we end up attempting to run the command by appending the string after each colon-separated component of PATH. The Cygwin environment supports both Windows and POSIX style paths, so both forwardslahes '/' and back slashes '\' can be used as directory separators for any external program the user supplies. Examples for path strings which are being incorrectly searched for in the PATH instead of being executed as is: - "C:\Program Files\some-program.exe" - "a\b\c.exe" To handle these, the PATH lookup detection logic in prepare_cmd() is taught to know about this Cygwin quirk, by introducing has_dir_sep(path) helper function to abstract away the difference between true POSIX and Cygwin systems. Signed-off-by: Andras Kucsma <r0maikx02b@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-03-09Merge branch 'am/mingw-poll-fix'Libravatar Junio C Hamano1-28/+3
MinGW's poll() emulation has been improved. * am/mingw-poll-fix: mingw: workaround for hangs when sending STDIN
2020-03-02Merge branch 'rs/micro-cleanups'Libravatar Junio C Hamano1-1/+1
Code cleanup. * rs/micro-cleanups: use strpbrk(3) to search for characters from a given set quote: use isalnum() to check for alphanumeric characters
2020-02-27mingw: workaround for hangs when sending STDINLibravatar Alexandr Miloslavskiy1-28/+3
Explanation ----------- The problem here is flawed `poll()` implementation. When it tries to see if pipe can be written without blocking, it eventually calls `NtQueryInformationFile()` and tests `WriteQuotaAvailable`. However, the meaning of quota was misunderstood. The value of quota is reduced when either some data was written to a pipe, *or* there is a pending read on the pipe. Therefore, if there is a pending read of size >= than the pipe's buffer size, poll() will think that pipe is not writable and will hang forever, usually that means deadlocking both pipe users. I have studied the problem and found that Windows pipes track two values: `QuotaUsed` and `BytesInQueue`. The code in `poll()` apparently wants to know `BytesInQueue` instead of quota. Unfortunately, `BytesInQueue` can only be requested from read end of the pipe, while `poll()` receives write end. The git's implementation of `poll()` was copied from gnulib, which also contains a flawed implementation up to today. I also had a look at implementation in cygwin, which is also broken in a subtle way. It uses this code in `pipe_data_available()`: fpli.WriteQuotaAvailable = (fpli.OutboundQuota - fpli.ReadDataAvailable) However, `ReadDataAvailable` always returns 0 for the write end of the pipe, turning the code into an obfuscated version of returning pipe's total buffer size, which I guess will in turn have `poll()` always say that pipe is writable. The commit that introduced the code doesn't say anything about this change, so it could be some debugging code that slipped in. These are the typical sizes used in git: 0x2000 - default read size in `strbuf_read()` 0x1000 - default read size in CRT, used by `strbuf_getwholeline()` 0x2000 - pipe buffer size in compat\mingw.c As a consequence, as soon as child process uses `strbuf_read()`, `poll()` in parent process will hang forever, deadlocking both processes. This results in two observable behaviors: 1) If parent process begins sending STDIN quickly (and usually that's the case), then first `poll()` will succeed and first block will go through. MAX_IO_SIZE_DEFAULT is 8MB, so if STDIN exceeds 8MB, then it will deadlock. 2) If parent process waits a little bit for any reason (including OS scheduler) and child is first to issue `strbuf_read()`, then it will deadlock immediately even on small STDINs. The problem is illustrated by `git stash push`, which will currently read the entire patch into memory and then send it to `git apply` via STDIN. If patch exceeds 8MB, git hangs on Windows. Possible solutions ------------------ 1) Somehow obtain `BytesInQueue` instead of `QuotaUsed` I did a pretty thorough search and didn't find any ways to obtain the value from write end of the pipe. 2) Also give read end of the pipe to `poll()` That can be done, but it will probably invite some dirty code, because `poll()` * can accept multiple pipes at once * can accept things that are not pipes * is expected to have a well known signature. 3) Make `poll()` always reply "writable" for write end of the pipe Afterall it seems that cygwin (accidentally?) does that for years. Also, it should be noted that `pump_io_round()` writes 8MB blocks, completely ignoring the fact that pipe's buffer size is only 8KB, which means that pipe gets clogged many times during that single write. This may invite a deadlock, if child's STDERR/STDOUT gets clogged while it's trying to deal with 8MB of STDIN. Such deadlocks could be defeated with writing less than pipe's buffer size per round, and always reading everything from STDOUT/STDERR before starting next round. Therefore, making `poll()` always reply "writable" shouldn't cause any new issues or block any future solutions. 4) Increase the size of the pipe's buffer The difference between `BytesInQueue` and `QuotaUsed` is the size of pending reads. Therefore, if buffer is bigger than size of reads, `poll()` won't hang so easily. However, I found that for example `strbuf_read()` will get more and more hungry as it reads large inputs, eventually surpassing any reasonable pipe buffer size. Chosen solution --------------- Make `poll()` always reply "writable" for write end of the pipe. Hopefully one day someone will find a way to implement it properly. Reproduction ------------ printf "%8388608s" X >large_file.txt git stash push --include-untracked -- large_file.txt I have decided not to include this as test to avoid slowing down the test suite. I don't expect the specific problem to come back, and chances are that `git stash push` will be reworked to avoid sending the entire patch via STDIN. Signed-off-by: Alexandr Miloslavskiy <alexandr.miloslavskiy@syntevo.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-24use strpbrk(3) to search for characters from a given setLibravatar René Scharfe1-1/+1
We can check if certain characters are present in a string by calling strchr(3) on each of them, or we can pass them all to a single strpbrk(3) call. The latter is shorter, less repetitive and slightly more efficient, so let's do that instead. Signed-off-by: René Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-17Merge branch 'js/mingw-open-in-gdb'Libravatar Junio C Hamano2-0/+23
Dev support. * js/mingw-open-in-gdb: mingw: add a helper function to attach GDB to the current process
2020-02-14mingw: add a helper function to attach GDB to the current processLibravatar Johannes Schindelin2-0/+23
When debugging Git, the criss-cross spawning of processes can make things quite a bit difficult, especially when a Unix shell script is thrown in the mix that calls a `git.exe` that then segfaults. To help debugging such things, we introduce the `open_in_gdb()` function which can be called at a code location where the segfault happens (or as close as one can get); This will open a new MinTTY window with a GDB that already attached to the current process. Inspired by Derrick Stolee. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-12Merge branch 'jk/clang-sanitizer-fixes'Libravatar Junio C Hamano1-2/+4
C pedantry ;-) fix. * jk/clang-sanitizer-fixes: obstack: avoid computing offsets from NULL pointer xdiff: avoid computing non-zero offset from NULL pointer avoid computing zero offsets from NULL pointer merge-recursive: use subtraction to flip stage merge-recursive: silence -Wxor-used-as-pow warning
2020-02-05Merge branch 'js/add-p-leftover-bits'Libravatar Junio C Hamano2-4/+248
The final leg of rewriting "add -i/-p" in C. * js/add-p-leftover-bits: ci: include the built-in `git add -i` in the `linux-gcc` job built-in add -p: handle Escape sequences more efficiently built-in add -p: handle Escape sequences in interactive.singlekey mode built-in add -p: respect the `interactive.singlekey` config setting terminal: add a new function to read a single keystroke terminal: accommodate Git for Windows' default terminal terminal: make the code of disable_echo() reusable built-in add -p: handle diff.algorithm built-in add -p: support interactive.diffFilter t3701: adjust difffilter test
2020-01-30Merge branch 'jk/asan-build-fix'Libravatar Junio C Hamano1-0/+5
Work around test breakages caused by custom regex engine used in libasan, when address sanitizer is used with more recent versions of gcc and clang. * jk/asan-build-fix: Makefile: use compat regex with SANITIZE=address
2020-01-28obstack: avoid computing offsets from NULL pointerLibravatar Jeff King1-2/+4
As with the previous two commits, UBSan with clang-11 complains about computing offsets from a NULL pointer. The failures in t4013 (and elsewhere) look like this: kwset.c:102:23: runtime error: applying non-zero offset 107820859019600 to null pointer ... not ok 79 - git log -SF master # magic is (not used) That line is not enlightening: ... = obstack_alloc(&kwset->obstack, sizeof (struct trie)); because obstack is implemented almost entirely in macros, and the actual problem is five macros deep (I temporarily converted them to inline functions to get better compiler errors, which was tedious but worked reasonably well). The actual problem is in these pointer-alignment macros: /* If B is the base of an object addressed by P, return the result of aligning P to the next multiple of A + 1. B and P must be of type char *. A + 1 must be a power of 2. */ #define __BPTR_ALIGN(B, P, A) ((B) + (((P) - (B) + (A)) & ~(A))) /* Similar to _BPTR_ALIGN (B, P, A), except optimize the common case where pointers can be converted to integers, aligned as integers, and converted back again. If PTR_INT_TYPE is narrower than a pointer (e.g., the AS/400), play it safe and compute the alignment relative to B. Otherwise, use the faster strategy of computing the alignment relative to 0. */ #define __PTR_ALIGN(B, P, A) \ __BPTR_ALIGN (sizeof (PTR_INT_TYPE) < sizeof (void *) ? (B) : (char *) 0, \ P, A) If we have a sufficiently-large integer pointer type, then we do the computation using a NULL pointer constant. That turns __BPTR_ALIGN() into something like: NULL + (P - NULL + A) & ~A and UBSan is complaining about adding the full value of P to that initial NULL. We can fix this by doing our math as an integer type, and then casting the result back to a pointer. The problem case only happens when we know that the integer type is large enough, so there should be no issue with truncation. Another option would be just simplify out all the 0's from __BPTR_ALIGN() for the NULL-pointer case. That probably wouldn't work for a platform where the NULL pointer isn't all-zeroes, but Git already wouldn't work on such a platform (due to our use of memset to set pointers in structs to NULL). But I tried here to keep as close to the original as possible. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-16Sync with maintLibravatar Junio C Hamano1-2/+2
* maint: msvc: accommodate for vcpkg's upgrade to OpenSSL v1.1.x
2020-01-16Makefile: use compat regex with SANITIZE=addressLibravatar Jeff King1-0/+5
Recent versions of the gcc and clang Address Sanitizer produce test failures related to regexec(). This triggers with gcc-10 and clang-8 (but not gcc-9 nor clang-7). Running: make CC=gcc-10 SANITIZE=address test results in failures in t4018, t3206, and t4062. The cause seems to be that when built with ASan, we use a different version of regexec() than normal. And this version doesn't understand the REG_STARTEND flag. Here's my evidence supporting that. The failure in t4062 is an ASan warning: expecting success of 4062.2 '-G matches': git diff --name-only -G "^(0{64}){64}$" HEAD^ >out && test 4096-zeroes.txt = "$(cat out)" ================================================================= ==672994==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x7fa76f672000 at pc 0x7fa7726f75b6 bp 0x7ffe41bdda70 sp 0x7ffe41bdd220 READ of size 4097 at 0x7fa76f672000 thread T0 #0 0x7fa7726f75b5 (/lib/x86_64-linux-gnu/libasan.so.6+0x4f5b5) #1 0x562ae0c9c40e in regexec_buf /home/peff/compile/git/git-compat-util.h:1117 #2 0x562ae0c9c40e in diff_grep /home/peff/compile/git/diffcore-pickaxe.c:52 #3 0x562ae0c9cc28 in pickaxe_match /home/peff/compile/git/diffcore-pickaxe.c:166 [...] In this case we're looking in a buffer which was mmap'd via reuse_worktree_file(), and whose size is 4096 bytes. But libasan's regex tries to look at byte 4097 anyway! If we tweak Git like this: diff --git a/diff.c b/diff.c index 8e2914c031..cfae60c120 100644 --- a/diff.c +++ b/diff.c @@ -3880,7 +3880,7 @@ static int reuse_worktree_file(struct index_state *istate, */ if (ce_uptodate(ce) || (!lstat(name, &st) && !ie_match_stat(istate, ce, &st, 0))) - return 1; + return 0; return 0; } to use a regular buffer (with a trailing NUL) instead of an mmap, then the complaint goes away. The other failures are actually diff output with an incorrect funcname header. If I instrument xdiff to show the funcname matching like so: diff --git a/xdiff-interface.c b/xdiff-interface.c index 8509f9ea22..f6c3dc1986 100644 --- a/xdiff-interface.c +++ b/xdiff-interface.c @@ -197,6 +197,7 @@ struct ff_regs { struct ff_reg { regex_t re; int negate; + char *printable; } *array; }; @@ -218,7 +219,12 @@ static long ff_regexp(const char *line, long len, for (i = 0; i < regs->nr; i++) { struct ff_reg *reg = regs->array + i; - if (!regexec_buf(&reg->re, line, len, 2, pmatch, 0)) { + int ret = regexec_buf(&reg->re, line, len, 2, pmatch, 0); + warning("regexec %s:\n regex: %s\n buf: %.*s", + ret == 0 ? "matched" : "did not match", + reg->printable, + (int)len, line); + if (!ret) { if (reg->negate) return -1; break; @@ -264,6 +270,7 @@ void xdiff_set_find_func(xdemitconf_t *xecfg, const char *value, int cflags) expression = value; if (regcomp(&reg->re, expression, cflags)) die("Invalid regexp to look for hunk header: %s", expression); + reg->printable = xstrdup(expression); free(buffer); value = ep + 1; } then when compiling with ASan and gcc-10, running the diff from t4018.66 produces this: $ git diff -U1 cpp-skip-access-specifiers warning: regexec did not match: regex: ^[ ]*[A-Za-z_][A-Za-z_0-9]*:[[:space:]]*($|/[/*]) buf: private: warning: regexec matched: regex: ^((::[[:space:]]*)?[A-Za-z_].*)$ buf: private: diff --git a/cpp-skip-access-specifiers b/cpp-skip-access-specifiers index 4d4a9db..ebd6f42 100644 --- a/cpp-skip-access-specifiers +++ b/cpp-skip-access-specifiers @@ -6,3 +6,3 @@ private: void DoSomething(); int ChangeMe; }; void DoSomething(); - int ChangeMe; + int IWasChanged; }; That first regex should match (and is negated, so it should be telling us _not_ to match "private:"). But it wouldn't if regexec() is looking at the whole buffer, and not just the length-limited line we've fed to regexec_buf(). So this is consistent again with REG_STARTEND being ignored. The correct output (compiling without ASan, or gcc-9 with Asan) looks like this: warning: regexec matched: regex: ^[ ]*[A-Za-z_][A-Za-z_0-9]*:[[:space:]]*($|/[/*]) buf: private: [...more lines that we end up not using...] warning: regexec matched: regex: ^((::[[:space:]]*)?[A-Za-z_].*)$ buf: class RIGHT : public Baseclass diff --git a/cpp-skip-access-specifiers b/cpp-skip-access-specifiers index 4d4a9db..ebd6f42 100644 --- a/cpp-skip-access-specifiers +++ b/cpp-skip-access-specifiers @@ -6,3 +6,3 @@ class RIGHT : public Baseclass void DoSomething(); - int ChangeMe; + int IWasChanged; }; So it really does seem like libasan's regex engine is ignoring REG_STARTEND. We should be able to work around it by compiling with NO_REGEX, which would use our local regexec(). But to make matters even more interesting, this isn't enough by itself. Because ASan has support from the compiler, it doesn't seem to intercept our call to regexec() at the dynamic library level. It actually recognizes when we are compiling a call to regexec() and replaces it with ASan-specific code at that point. And unlike most of our other compat code, where we might have git_mmap() or similar, the actual symbol name in the compiled compat/regex code is regexec(). So just compiling with NO_REGEX isn't enough; we still end up in libasan! We can work around that by having the preprocessor replace regexec with git_regexec (both in the callers and in the actual implementation), and we truly end up with a call to our custom regex code, even when compiling with ASan. That's probably a good thing to do anyway, as it means anybody looking at the symbols later (e.g., in a debugger) would have a better indication of which function is which. So we'll do the same for the other common regex functions (even though just regexec() is enough to fix this ASan problem). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-16msvc: accommodate for vcpkg's upgrade to OpenSSL v1.1.xLibravatar Johannes Schindelin1-2/+2
With the upgrade, the library names changed from libeay32/ssleay32 to libcrypto/libssl. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-15built-in add -p: handle Escape sequences more efficientlyLibravatar Johannes Schindelin1-1/+72
When `interactive.singlekey = true`, we react immediately to keystrokes, even to Escape sequences (e.g. when pressing a cursor key). The problem with Escape sequences is that we do not really know when they are done, and as a heuristic we poll standard input for half a second to make sure that we got all of it. While waiting half a second is not asking for a whole lot, it can become quite annoying over time, therefore with this patch, we read the terminal capabilities (if available) and extract known Escape sequences from there, then stop polling immediately when we detected that the user pressed a key that generated such a known sequence. This recapitulates the remaining part of b5cc003253c8 (add -i: ignore terminal escape sequences, 2011-05-17). Note: We do *not* query the terminal capabilities directly. That would either require a lot of platform-specific code, or it would require linking to a library such as ncurses. Linking to a library in the built-ins is something we try very hard to avoid (we even kicked the libcurl dependency to a non-built-in remote helper, just to shave off a tiny fraction of a second from Git's startup time). And the platform-specific code would be a maintenance nightmare. Even worse: in Git for Windows' case, we would need to query MSYS2 pseudo terminals, which `git.exe` simply cannot do (because it is intentionally *not* an MSYS2 program). To address this, we simply spawn `infocmp -L -1` and parse its output (which works even in Git for Windows, because that helper is included in the end-user facing installations). This is done only once, as in the Perl version, but it is done only when the first Escape sequence is encountered, not upon startup of `git add -i`; This saves on startup time, yet makes reacting to the first Escape sequence slightly more sluggish. But it allows us to keep the terminal-related code encapsulated in the `compat/terminal.c` file. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-15built-in add -p: handle Escape sequences in interactive.singlekey modeLibravatar Johannes Schindelin1-1/+55
This recapitulates part of b5cc003253c8 (add -i: ignore terminal escape sequences, 2011-05-17): add -i: ignore terminal escape sequences On the author's terminal, the up-arrow input sequence is ^[[A, and thus fat-fingering an up-arrow into 'git checkout -p' is quite dangerous: git-add--interactive.perl will ignore the ^[ and [ characters and happily treat A as "discard everything". As a band-aid fix, use Term::Cap to get all terminal capabilities. Then use the heuristic that any capability value that starts with ^[ (i.e., \e in perl) must be a key input sequence. Finally, given an input that starts with ^[, read more characters until we have read a full escape sequence, then return that to the caller. We use a timeout of 0.5 seconds on the subsequent reads to avoid getting stuck if the user actually input a lone ^[. Since none of the currently recognized keys start with ^[, the net result is that the sequence as a whole will be ignored and the help displayed. Note that we leave part for later which uses "Term::Cap to get all terminal capabilities", for several reasons: 1. it is actually not really necessary, as the timeout of 0.5 seconds should be plenty sufficient to catch Escape sequences, 2. it is cleaner to keep the change to special-case Escape sequences separate from the change that reads all terminal capabilities to speed things up, and 3. in practice, relying on the terminal capabilities is a bit overrated, as the information could be incomplete, or plain wrong. For example, in this developer's tmux sessions, the terminal capabilities claim that the "cursor up" sequence is ^[M, but the actual sequence produced by the "cursor up" key is ^[[A. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-15terminal: add a new function to read a single keystrokeLibravatar Johannes Schindelin2-0/+58
Typically, input on the command-line is line-based. It is actually not really easy to get single characters (or better put: keystrokes). We provide two implementations here: - One that handles `/dev/tty` based systems as well as native Windows. The former uses the `tcsetattr()` function to put the terminal into "raw mode", which allows us to read individual keystrokes, one by one. The latter uses `stty.exe` to do the same, falling back to direct Win32 Console access. Thanks to the refactoring leading up to this commit, this is a single function, with the platform-specific details hidden away in conditionally-compiled code blocks. - A fall-back which simply punts and reads back an entire line. Note that the function writes the keystroke into an `strbuf` rather than a `char`, in preparation for reading Escape sequences (e.g. when the user hit an arrow key). This is also required for UTF-8 sequences in case the keystroke corresponds to a non-ASCII letter. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-15terminal: accommodate Git for Windows' default terminalLibravatar Johannes Schindelin1-0/+50
Git for Windows' Git Bash runs in MinTTY by default, which does not have a Win32 Console instance, but uses MSYS2 pseudo terminals instead. This is a problem, as Git for Windows does not want to use the MSYS2 emulation layer for Git itself, and therefore has no direct way to interact with that pseudo terminal. As a workaround, use the `stty` utility (which is included in Git for Windows, and which *is* an MSYS2 program, so it knows how to deal with the pseudo terminal). Note: If Git runs in a regular CMD or PowerShell window, there *is* a regular Win32 Console to work with. This is not a problem for the MSYS2 `stty`: it copes with this scenario just fine. Also note that we introduce support for more bits than would be necessary for a mere `disable_echo()` here, in preparation for the upcoming `enable_non_canonical()` function. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-15terminal: make the code of disable_echo() reusableLibravatar Johannes Schindelin1-4/+15
We are about to introduce the function `enable_non_canonical()`, which shares almost the complete code with `disable_echo()`. Let's prepare for that, by refactoring out that shared code. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-02Merge branch 'js/mingw-reserved-filenames'Libravatar Junio C Hamano2-22/+111
Forbid pathnames that the platform's filesystem cannot represent on MinGW. * js/mingw-reserved-filenames: mingw: refuse paths containing reserved names mingw: short-circuit the conversion of `/dev/null` to UTF-16
2019-12-21mingw: refuse paths containing reserved namesLibravatar Johannes Schindelin2-16/+99
There are a couple of reserved names that cannot be file names on Windows, such as `AUX`, `NUL`, etc. For an almost complete list, see https://docs.microsoft.com/en-us/windows/win32/fileio/naming-a-file If one would try to create a directory named `NUL`, it would actually "succeed", i.e. the call would return success, but nothing would be created. Worse, even adding a file extension to the reserved name does not make it a valid file name. To understand the rationale behind that behavior, see https://devblogs.microsoft.com/oldnewthing/20031022-00/?p=42073 Let's just disallow them all. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-12-21mingw: short-circuit the conversion of `/dev/null` to UTF-16Libravatar Johannes Schindelin1-10/+16
In the next commit, we want to disallow accessing any path that contains any segment that is equivalent to `NUL`. In particular, we want to disallow accessing `NUL` (e.g. to prevent any repository from being checked out that contains a file called `NUL`, as that is not a valid file name on Windows). However, there are legitimate use cases within Git itself to write to the Null device. As Git is really a Linux project, it does not abstract that idea, though, but instead uses `/dev/null` to describe this intention. So let's side-step the validation _specifically_ in the case that we want to write to (or read from) `/dev/null`, via a dedicated short-cut in the code that skips the call to `validate_win32_path()`. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-12-16Merge branch 'dd/time-reentrancy'Libravatar Junio C Hamano1-6/+6
Avoid gmtime() and localtime() and prefer their reentrant counterparts. * dd/time-reentrancy: mingw: use {gm,local}time_s as backend for {gm,local}time_r archive-zip.c: switch to reentrant localtime_r date.c: switch to reentrant {gm,local}time_r
2019-12-10Merge branch 'js/mingw-inherit-only-std-handles'Libravatar Junio C Hamano2-12/+145
Work around a issue where a FD that is left open when spawning a child process and is kept open in the child can interfere with the operation in the parent process on Windows. * js/mingw-inherit-only-std-handles: mingw: forbid translating ERROR_SUCCESS to an errno value mingw: do set `errno` correctly when trying to restrict handle inheritance mingw: restrict file handle inheritance only on Windows 7 and later mingw: spawned processes need to inherit only standard handles mingw: work around incorrect standard handles mingw: demonstrate that all file handles are inherited by child processes
2019-12-09Sync with Git 2.24.1Libravatar Junio C Hamano4-11/+133
2019-12-06Sync with 2.23.1Libravatar Johannes Schindelin4-11/+133
* maint-2.23: (44 commits) Git 2.23.1 Git 2.22.2 Git 2.21.1 mingw: sh arguments need quoting in more circumstances mingw: fix quoting of empty arguments for `sh` mingw: use MSYS2 quoting even when spawning shell scripts mingw: detect when MSYS2's sh is to be spawned more robustly t7415: drop v2.20.x-specific work-around Git 2.20.2 t7415: adjust test for dubiously-nested submodule gitdirs for v2.20.x Git 2.19.3 Git 2.18.2 Git 2.17.3 Git 2.16.6 test-drop-caches: use `has_dos_drive_prefix()` Git 2.15.4 Git 2.14.6 mingw: handle `subst`-ed "DOS drives" mingw: refuse to access paths with trailing spaces or periods mingw: refuse to access paths with illegal characters ...
2019-12-06Sync with 2.22.2Libravatar Johannes Schindelin4-11/+133
* maint-2.22: (43 commits) Git 2.22.2 Git 2.21.1 mingw: sh arguments need quoting in more circumstances mingw: fix quoting of empty arguments for `sh` mingw: use MSYS2 quoting even when spawning shell scripts mingw: detect when MSYS2's sh is to be spawned more robustly t7415: drop v2.20.x-specific work-around Git 2.20.2 t7415: adjust test for dubiously-nested submodule gitdirs for v2.20.x Git 2.19.3 Git 2.18.2 Git 2.17.3 Git 2.16.6 test-drop-caches: use `has_dos_drive_prefix()` Git 2.15.4 Git 2.14.6 mingw: handle `subst`-ed "DOS drives" mingw: refuse to access paths with trailing spaces or periods mingw: refuse to access paths with illegal characters unpack-trees: let merged_entry() pass through do_add_entry()'s errors ...
2019-12-06Sync with 2.21.1Libravatar Johannes Schindelin4-11/+133
* maint-2.21: (42 commits) Git 2.21.1 mingw: sh arguments need quoting in more circumstances mingw: fix quoting of empty arguments for `sh` mingw: use MSYS2 quoting even when spawning shell scripts mingw: detect when MSYS2's sh is to be spawned more robustly t7415: drop v2.20.x-specific work-around Git 2.20.2 t7415: adjust test for dubiously-nested submodule gitdirs for v2.20.x Git 2.19.3 Git 2.18.2 Git 2.17.3 Git 2.16.6 test-drop-caches: use `has_dos_drive_prefix()` Git 2.15.4 Git 2.14.6 mingw: handle `subst`-ed "DOS drives" mingw: refuse to access paths with trailing spaces or periods mingw: refuse to access paths with illegal characters unpack-trees: let merged_entry() pass through do_add_entry()'s errors quote-stress-test: offer to test quoting arguments for MSYS2 sh ...
2019-12-06mingw: sh arguments need quoting in more circumstancesLibravatar Johannes Schindelin1-2/+3
Previously, we failed to quote characters such as '*', '(' and the likes. Let's fix this. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2019-12-06mingw: fix quoting of empty arguments for `sh`Libravatar Johannes Schindelin1-1/+1
When constructing command-lines to spawn processes, it is an unfortunate but necessary decision to quote arguments differently: MSYS2 has different dequoting rules (inherited from Cygwin) than the rest of Windows. To accommodate that, Git's Windows compatibility layer has two separate quoting helpers, one for MSYS2 (which it uses exclusively when spawning `sh`) and the other for regular Windows executables. The MSYS2 one had an unfortunate bug where a `,` somehow slipped in, instead of the `;`. As a consequence, empty arguments would not be enclosed in a pair of double quotes, but the closing double quote was skipped. Let's fix this. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2019-12-06mingw: use MSYS2 quoting even when spawning shell scriptsLibravatar Johannes Schindelin1-1/+2
At the point where `mingw_spawn_fd()` is called, we already have a full path to the script interpreter in that scenario, and we pass it in as the executable to run, while the `argv` reflect what the script should receive as command-line. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2019-12-06mingw: detect when MSYS2's sh is to be spawned more robustlyLibravatar Johannes Schindelin1-1/+14
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2019-12-06Sync with 2.20.2Libravatar Johannes Schindelin4-6/+113
* maint-2.20: (36 commits) Git 2.20.2 t7415: adjust test for dubiously-nested submodule gitdirs for v2.20.x Git 2.19.3 Git 2.18.2 Git 2.17.3 Git 2.16.6 test-drop-caches: use `has_dos_drive_prefix()` Git 2.15.4 Git 2.14.6 mingw: handle `subst`-ed "DOS drives" mingw: refuse to access paths with trailing spaces or periods mingw: refuse to access paths with illegal characters unpack-trees: let merged_entry() pass through do_add_entry()'s errors quote-stress-test: offer to test quoting arguments for MSYS2 sh t6130/t9350: prepare for stringent Win32 path validation quote-stress-test: allow skipping some trials quote-stress-test: accept arguments to test via the command-line tests: add a helper to stress test argument quoting mingw: fix quoting of arguments Disallow dubiously-nested submodule git directories ...
2019-12-06Sync with 2.19.3Libravatar Johannes Schindelin2-6/+112
* maint-2.19: (34 commits) Git 2.19.3 Git 2.18.2 Git 2.17.3 Git 2.16.6 test-drop-caches: use `has_dos_drive_prefix()` Git 2.15.4 Git 2.14.6 mingw: handle `subst`-ed "DOS drives" mingw: refuse to access paths with trailing spaces or periods mingw: refuse to access paths with illegal characters unpack-trees: let merged_entry() pass through do_add_entry()'s errors quote-stress-test: offer to test quoting arguments for MSYS2 sh t6130/t9350: prepare for stringent Win32 path validation quote-stress-test: allow skipping some trials quote-stress-test: accept arguments to test via the command-line tests: add a helper to stress test argument quoting mingw: fix quoting of arguments Disallow dubiously-nested submodule git directories protect_ntfs: turn on NTFS protection by default path: also guard `.gitmodules` against NTFS Alternate Data Streams ...
2019-12-06Sync with 2.18.2Libravatar Johannes Schindelin2-6/+112
* maint-2.18: (33 commits) Git 2.18.2 Git 2.17.3 Git 2.16.6 test-drop-caches: use `has_dos_drive_prefix()` Git 2.15.4 Git 2.14.6 mingw: handle `subst`-ed "DOS drives" mingw: refuse to access paths with trailing spaces or periods mingw: refuse to access paths with illegal characters unpack-trees: let merged_entry() pass through do_add_entry()'s errors quote-stress-test: offer to test quoting arguments for MSYS2 sh t6130/t9350: prepare for stringent Win32 path validation quote-stress-test: allow skipping some trials quote-stress-test: accept arguments to test via the command-line tests: add a helper to stress test argument quoting mingw: fix quoting of arguments Disallow dubiously-nested submodule git directories protect_ntfs: turn on NTFS protection by default path: also guard `.gitmodules` against NTFS Alternate Data Streams is_ntfs_dotgit(): speed it up ...
2019-12-06Sync with 2.17.3Libravatar Johannes Schindelin2-6/+112
* maint-2.17: (32 commits) Git 2.17.3 Git 2.16.6 test-drop-caches: use `has_dos_drive_prefix()` Git 2.15.4 Git 2.14.6 mingw: handle `subst`-ed "DOS drives" mingw: refuse to access paths with trailing spaces or periods mingw: refuse to access paths with illegal characters unpack-trees: let merged_entry() pass through do_add_entry()'s errors quote-stress-test: offer to test quoting arguments for MSYS2 sh t6130/t9350: prepare for stringent Win32 path validation quote-stress-test: allow skipping some trials quote-stress-test: accept arguments to test via the command-line tests: add a helper to stress test argument quoting mingw: fix quoting of arguments Disallow dubiously-nested submodule git directories protect_ntfs: turn on NTFS protection by default path: also guard `.gitmodules` against NTFS Alternate Data Streams is_ntfs_dotgit(): speed it up mingw: disallow backslash characters in tree objects' file names ...
2019-12-06Sync with 2.16.6Libravatar Johannes Schindelin2-6/+112
* maint-2.16: (31 commits) Git 2.16.6 test-drop-caches: use `has_dos_drive_prefix()` Git 2.15.4 Git 2.14.6 mingw: handle `subst`-ed "DOS drives" mingw: refuse to access paths with trailing spaces or periods mingw: refuse to access paths with illegal characters unpack-trees: let merged_entry() pass through do_add_entry()'s errors quote-stress-test: offer to test quoting arguments for MSYS2 sh t6130/t9350: prepare for stringent Win32 path validation quote-stress-test: allow skipping some trials quote-stress-test: accept arguments to test via the command-line tests: add a helper to stress test argument quoting mingw: fix quoting of arguments Disallow dubiously-nested submodule git directories protect_ntfs: turn on NTFS protection by default path: also guard `.gitmodules` against NTFS Alternate Data Streams is_ntfs_dotgit(): speed it up mingw: disallow backslash characters in tree objects' file names path: safeguard `.git` against NTFS Alternate Streams Accesses ...
2019-12-06Sync with 2.15.4Libravatar Johannes Schindelin2-6/+112
* maint-2.15: (29 commits) Git 2.15.4 Git 2.14.6 mingw: handle `subst`-ed "DOS drives" mingw: refuse to access paths with trailing spaces or periods mingw: refuse to access paths with illegal characters unpack-trees: let merged_entry() pass through do_add_entry()'s errors quote-stress-test: offer to test quoting arguments for MSYS2 sh t6130/t9350: prepare for stringent Win32 path validation quote-stress-test: allow skipping some trials quote-stress-test: accept arguments to test via the command-line tests: add a helper to stress test argument quoting mingw: fix quoting of arguments Disallow dubiously-nested submodule git directories protect_ntfs: turn on NTFS protection by default path: also guard `.gitmodules` against NTFS Alternate Data Streams is_ntfs_dotgit(): speed it up mingw: disallow backslash characters in tree objects' file names path: safeguard `.git` against NTFS Alternate Streams Accesses clone --recurse-submodules: prevent name squatting on Windows is_ntfs_dotgit(): only verify the leading segment ...
2019-12-06Sync with 2.14.6Libravatar Johannes Schindelin2-6/+112
* maint-2.14: (28 commits) Git 2.14.6 mingw: handle `subst`-ed "DOS drives" mingw: refuse to access paths with trailing spaces or periods mingw: refuse to access paths with illegal characters unpack-trees: let merged_entry() pass through do_add_entry()'s errors quote-stress-test: offer to test quoting arguments for MSYS2 sh t6130/t9350: prepare for stringent Win32 path validation quote-stress-test: allow skipping some trials quote-stress-test: accept arguments to test via the command-line tests: add a helper to stress test argument quoting mingw: fix quoting of arguments Disallow dubiously-nested submodule git directories protect_ntfs: turn on NTFS protection by default path: also guard `.gitmodules` against NTFS Alternate Data Streams is_ntfs_dotgit(): speed it up mingw: disallow backslash characters in tree objects' file names path: safeguard `.git` against NTFS Alternate Streams Accesses clone --recurse-submodules: prevent name squatting on Windows is_ntfs_dotgit(): only verify the leading segment test-path-utils: offer to run a protectNTFS/protectHFS benchmark ...
2019-12-05Merge branch 'win32-accommodate-funny-drive-names'Libravatar Johannes Schindelin2-4/+41
While the only permitted drive letters for physical drives on Windows are letters of the US-English alphabet, this restriction does not apply to virtual drives assigned via `subst <letter>: <path>`. To prevent targeted attacks against systems where "funny" drive letters such as `1` or `!` are assigned, let's handle them as regular drive letters on Windows. This fixes CVE-2019-1351. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2019-12-05Merge branch 'win32-filenames-cannot-have-trailing-spaces-or-periods'Libravatar Johannes Schindelin2-1/+67
On Windows, filenames cannot have trailing spaces or periods, when opening such paths, they are stripped automatically. Read: you can open the file `README` via the file name `README . . .`. This ambiguity can be used in combination with other security bugs to cause e.g. remote code execution during recursive clones. This patch series fixes that. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2019-12-05mingw: handle `subst`-ed "DOS drives"Libravatar Johannes Schindelin2-2/+26
Over a decade ago, in 25fe217b86c (Windows: Treat Windows style path names., 2008-03-05), Git was taught to handle absolute Windows paths, i.e. paths that start with a drive letter and a colon. Unbeknownst to us, while drive letters of physical drives are limited to letters of the English alphabet, there is a way to assign virtual drive letters to arbitrary directories, via the `subst` command, which is _not_ limited to English letters. It is therefore possible to have absolute Windows paths of the form `1:\what\the\hex.txt`. Even "better": pretty much arbitrary Unicode letters can also be used, e.g. `ä:\tschibät.sch`. While it can be sensibly argued that users who set up such funny drive letters really seek adverse consequences, the Windows Operating System is known to be a platform where many users are at the mercy of administrators who have their very own idea of what constitutes a reasonable setup. Therefore, let's just make sure that such funny paths are still considered absolute paths by Git, on Windows. In addition to Unicode characters, pretty much any character is a valid drive letter, as far as `subst` is concerned, even `:` and `"` or even a space character. While it is probably the opposite of smart to use them, let's safeguard `is_dos_drive_prefix()` against all of them. Note: `[::1]:repo` is a valid URL, but not a valid path on Windows. As `[` is now considered a valid drive letter, we need to be very careful to avoid misinterpreting such a string as valid local path in `url_is_local_not_ssh()`. To do that, we use the just-introduced function `is_valid_path()` (which will label the string as invalid file name because of the colon characters). This fixes CVE-2019-1351. Reported-by: Nicolas Joly <Nicolas.Joly@microsoft.com> Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2019-12-05mingw: refuse to access paths with trailing spaces or periodsLibravatar Johannes Schindelin2-1/+67
When creating a directory on Windows whose path ends in a space or a period (or chains thereof), the Win32 API "helpfully" trims those. For example, `mkdir("abc ");` will return success, but actually create a directory called `abc` instead. This stems back to the DOS days, when all file names had exactly 8 characters plus exactly 3 characters for the file extension, and the only way to have shorter names was by padding with spaces. Sadly, this "helpful" behavior is a bit inconsistent: after a successful `mkdir("abc ");`, a `mkdir("abc /def")` will actually _fail_ (because the directory `abc ` does not actually exist). Even if it would work, we now have a serious problem because a Git repository could contain directories `abc` and `abc `, and on Windows, they would be "merged" unintentionally. As these paths are illegal on Windows, anyway, let's disallow any accesses to such paths on that Operating System. For practical reasons, this behavior is still guarded by the config setting `core.protectNTFS`: it is possible (and at least two regression tests make use of it) to create commits without involving the worktree. In such a scenario, it is of course possible -- even on Windows -- to create such file names. Among other consequences, this patch disallows submodules' paths to end in spaces on Windows (which would formerly have confused Git enough to try to write into incorrect paths, anyway). While this patch does not fix a vulnerability on its own, it prevents an attack vector that was exploited in demonstrations of a number of recently-fixed security bugs. The regression test added to `t/t7417-submodule-path-url.sh` reflects that attack vector. Note that we have to adjust the test case "prevent git~1 squatting on Windows" in `t/t7415-submodule-names.sh` because of a very subtle issue. It tries to clone two submodules whose names differ only in a trailing period character, and as a consequence their git directories differ in the same way. Previously, when Git tried to clone the second submodule, it thought that the git directory already existed (because on Windows, when you create a directory with the name `b.` it actually creates `b`), but with this patch, the first submodule's clone will fail because of the illegal name of the git directory. Therefore, when cloning the second submodule, Git will take a different code path: a fresh clone (without an existing git directory). Both code paths fail to clone the second submodule, both because the the corresponding worktree directory exists and is not empty, but the error messages are worded differently. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2019-12-05mingw: refuse to access paths with illegal charactersLibravatar Johannes Schindelin2-2/+15
Certain characters are not admissible in file names on Windows, even if Cygwin/MSYS2 (and therefore, Git for Windows' Bash) pretend that they are, e.g. `:`, `<`, `>`, etc Let's disallow those characters explicitly in Windows builds of Git. Note: just like trailing spaces or periods, it _is_ possible on Windows to create commits adding files with such illegal characters, as long as the operation leaves the worktree untouched. To allow for that, we continue to guard `is_valid_win32_path()` behind the config setting `core.protectNTFS`, so that users _can_ continue to do that, as long as they turn the protections off via that config setting. Among other problems, this prevents Git from trying to write to an "NTFS Alternate Data Stream" (which refers to metadata stored alongside a file, under a special name: "<filename>:<stream-name>"). This fix therefore also prevents an attack vector that was exploited in demonstrations of a number of recently-fixed security bugs. Further reading on illegal characters in Win32 filenames: https://docs.microsoft.com/en-us/windows/win32/fileio/naming-a-file Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>