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2020-04-28Merge branch 'jk/fast-import-use-hashmap'Libravatar Junio C Hamano1-25/+36
The custom hash function used by "git fast-import" has been replaced with the one from hashmap.c, which gave us a nice performance boost. * jk/fast-import-use-hashmap: fast-import: replace custom hash with hashmap.c
2020-04-06fast-import: replace custom hash with hashmap.cLibravatar Jeff King1-25/+36
We use a custom hash in fast-import to store the set of objects we've imported so far. It has a fixed set of 2^16 buckets and chains any collisions with a linked list. As the number of objects grows larger than that, the load factor increases and we degrade to O(n) lookups and O(n^2) insertions. We can scale better by using our hashmap.c implementation, which will resize the bucket count as we grow. This does incur an extra memory cost of 8 bytes per object, as hashmap stores the integer hash value for each entry in its hashmap_entry struct (which we really don't care about here, because we're just reusing the embedded object hash). But I think the numbers below justify this (and our per-object memory cost is already much higher). I also looked at using khash, but it seemed to perform slightly worse than hashmap at all sizes, and worse even than the existing code for small sizes. It's also awkward to use here, because we want to look up a "struct object_entry" from a "struct object_id", and it doesn't handle mismatched keys as well. Making a mapping of object_id to object_entry would be more natural, but that would require pulling the embedded oid out of the object_entry or incurring an extra 32 bytes per object. In a synthetic test creating as many cheap, tiny objects as possible perl -e ' my $bits = shift; my $nr = 2**$bits; for (my $i = 0; $i < $nr; $i++) { print "blob\n"; print "data 4\n"; print pack("N", $i); } ' $bits | git fast-import I got these results: nr_objects master khash hashmap 2^20 0m4.317s 0m5.109s 0m3.890s 2^21 0m10.204s 0m9.702s 0m7.933s 2^22 0m27.159s 0m17.911s 0m16.751s 2^23 1m19.038s 0m35.080s 0m31.963s 2^24 4m18.766s 1m10.233s 1m6.793s which points to hashmap as the winner. We didn't have any perf tests for fast-export or fast-import, so I added one as a more real-world case. It uses an export without blobs since that's significantly cheaper than a full one, but still is an interesting case people might use (e.g., for rewriting history). It will emphasize this change in some ways (as a percentage we spend more time making objects and less shuffling blob bytes around) and less in others (the total object count is lower). Here are the results for linux.git: Test HEAD^ HEAD ---------------------------------------------------------------------------- 9300.1: export (no-blobs) 67.64(66.96+0.67) 67.81(67.06+0.75) +0.3% 9300.2: import (no-blobs) 284.04(283.34+0.69) 198.09(196.01+0.92) -30.3% It only has ~5.2M commits and trees, so this is a larger effect than I expected (the 2^23 case above only improved by 50s or so, but here we gained almost 90s). This is probably due to actually performing more object lookups in a real import with trees and commits, as opposed to just dumping a bunch of blobs into a pack. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-28fast-import: add options for rewriting submodulesLibravatar brian m. carlson1-5/+107
When converting a repository using submodules from one hash algorithm to another, it is necessary to rewrite the submodules from the old algorithm to the new algorithm, since only references to submodules, not their contents, are written to the fast-export stream. Without rewriting the submodules, fast-import fails with an "Invalid dataref" error when encountering a submodule in another algorithm. Add a pair of options, --rewrite-submodules-from and --rewrite-submodules-to, that take a list of marks produced by fast-export and fast-import, respectively, when processing the submodule. Use these marks to map the submodule commits from the old algorithm to the new algorithm. We read marks into two corresponding struct mark_set objects and then perform a mapping from the old to the new using a hash table. This lets us reuse the same mark parsing code that is used elsewhere and allows us to efficiently read and match marks based on their ID, since mark files need not be sorted. Note that because we're using a khash table for the object IDs, and this table copies values of struct object_id instead of taking references to them, it's necessary to zero the struct object_id values that we use to insert and look up in the table. Otherwise, we would end up with SHA-1 values that don't match because of whatever stack garbage might be left in the unused area. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-28fast-import: add a generic function to iterate over marksLibravatar brian m. carlson1-24/+26
Currently, we can iterate over marks only to dump them to a file. In the future, we'll want to perform an arbitrary operation over the items of a mark set. Add a function, for_each_mark, that iterates over marks in a set and performs an arbitrary callback function for each mark. Switch the mark dumping routine to use this function now that it's available. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-28fast-import: make find_marks work on any mark setLibravatar brian m. carlson1-11/+10
In the future, we'll use multiple different mark sets with this function, so make it take an argument that points to the mark set to operate on. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-28fast-import: add helper function for inserting mark object entriesLibravatar brian m. carlson1-15/+22
Currently, everything we want to insert into a mark set is an object entry. However, in the future, we will want to insert objects of other types. Teach read_mark_file to take a function pointer which helps us insert the object we want into our mark set. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-28fast-import: permit reading multiple marks filesLibravatar brian m. carlson1-14/+18
In the future, we'll want to read marks files for submodules as well. Refactor the existing code to make it possible to read multiple marks files, each into their own marks set. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-12-06Sync with 2.23.1Libravatar Johannes Schindelin1-4/+35
* 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 Schindelin1-4/+35
* 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 Schindelin1-4/+35
* 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 ...
2019-12-06Sync with 2.20.2Libravatar Johannes Schindelin1-4/+35
* 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 Schindelin1-4/+35
* 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 Schindelin1-4/+35
* 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 Schindelin1-4/+35
* 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 Schindelin1-4/+35
* 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 Schindelin1-4/+35
* 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 Schindelin1-4/+35
* 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 ...
2019-12-04fast-import: disallow "feature import-marks" by defaultLibravatar Jeff King1-0/+2
As with export-marks in the previous commit, import-marks can access the filesystem. This is significantly less dangerous than export-marks because it only involves reading from arbitrary paths, rather than writing them. However, it could still be surprising and have security implications (e.g., exfiltrating data from a service that accepts fast-import streams). Let's lump it (and its "if-exists" counterpart) in with export-marks, and enable the in-stream version only if --allow-unsafe-features is set. Signed-off-by: Jeff King <peff@peff.net>
2019-12-04fast-import: disallow "feature export-marks" by defaultLibravatar Jeff King1-0/+25
The fast-import stream command "feature export-marks=<path>" lets the stream write marks to an arbitrary path. This may be surprising if you are running fast-import against an untrusted input (which otherwise cannot do anything except update Git objects and refs). Let's disallow the use of this feature by default, and provide a command-line option to re-enable it (you can always just use the command-line --export-marks as well, but the in-stream version provides an easy way for exporters to control the process). This is a backwards-incompatible change, since the default is flipping to the new, safer behavior. However, since the main users of the in-stream versions would be import/export-based remote helpers, and since we trust remote helpers already (which are already running arbitrary code), we'll pass the new option by default when reading a remote helper's stream. This should minimize the impact. Note that the implementation isn't totally simple, as we have to work around the fact that fast-import doesn't parse its command-line options until after it has read any "feature" lines from the stream. This is how it lets command-line options override in-stream. But in our case, it's important to parse the new --allow-unsafe-features first. There are three options for resolving this: 1. Do a separate "early" pass over the options. This is easy for us to do because there are no command-line options that allow the "unstuck" form (so there's no chance of us mistaking an argument for an option), though it does introduce a risk of incorrect parsing later (e.g,. if we convert to parse-options). 2. Move the option parsing phase back to the start of the program, but teach the stream-reading code never to override an existing value. This is tricky, because stream "feature" lines override each other (meaning we'd have to start tracking the source for every option). 3. Accept that we might parse a "feature export-marks" line that is forbidden, as long we don't _act_ on it until after we've parsed the command line options. This would, in fact, work with the current code, but only because the previous patch fixed the export-marks parser to avoid touching the filesystem. So while it works, it does carry risk of somebody getting it wrong in the future in a rather subtle and unsafe way. I've gone with option (1) here as simple, safe, and unlikely to cause regressions. This fixes CVE-2019-1348. Signed-off-by: Jeff King <peff@peff.net>
2019-12-04fast-import: delay creating leading directories for export-marksLibravatar Jeff King1-1/+6
When we parse the --export-marks option, we don't immediately open the file, but we do create any leading directories. This can be especially confusing when a command-line option overrides an in-stream one, in which case we'd create the leading directory for the in-stream file, even though we never actually write the file. Let's instead create the directories just before opening the file, which means we'll create only useful directories. Note that this could change the handling of relative paths if we chdir() in between, but we don't actually do so; the only permanent chdir is from setup_git_directory() which runs before either code path (potentially we should take the pre-setup dir into account to avoid surprising the user, but that's an orthogonal change). The test just adapts the existing "override" test to use paths with leading directories. This checks both that the correct directory is created (which worked before but was not tested), and that the overridden one is not (our new fix here). While we're here, let's also check the error result of safe_create_leading_directories(). We'd presumably notice any failure immediately after when we try to open the file itself, but we can give a more specific error message in this case. Signed-off-by: Jeff King <peff@peff.net>
2019-12-04fast-import: stop creating leading directories for import-marksLibravatar Jeff King1-1/+0
When asked to import marks from "subdir/file.marks", we create the leading directory "subdir" if it doesn't exist. This makes no sense for importing marks, where we only ever open the path for reading. Most of the time this would be a noop, since if the marks file exists, then the leading directories exist, too. But if it doesn't (e.g., because --import-marks-if-exists was used), then we'd create the useless directory. This dates back to 580d5f83e7 (fast-import: always create marks_file directories, 2010-03-29). Even then it was useless, so it seems to have been added in error alongside the --export-marks case (which _is_ helpful). Signed-off-by: Jeff King <peff@peff.net>
2019-12-04fast-import: tighten parsing of boolean command line optionsLibravatar Jeff King1-2/+2
We parse options like "--max-pack-size=" using skip_prefix(), which makes sense to get at the bytes after the "=". However, we also parse "--quiet" and "--stats" with skip_prefix(), which allows things like "--quiet-nonsense" to behave like "--quiet". This was a mistaken conversion in 0f6927c229 (fast-import: put option parsing code in separate functions, 2009-12-04). Let's tighten this to an exact match, which was the original intent. Signed-off-by: Jeff King <peff@peff.net>
2019-10-15Merge branch 'en/fast-imexport-nested-tags'Libravatar Junio C Hamano1-11/+81
Updates to fast-import/export. * en/fast-imexport-nested-tags: fast-export: handle nested tags t9350: add tests for tags of things other than a commit fast-export: allow user to request tags be marked with --mark-tags fast-export: add support for --import-marks-if-exists fast-import: add support for new 'alias' command fast-import: allow tags to be identified by mark labels fast-import: fix handling of deleted tags fast-export: fix exporting a tag and nothing else
2019-10-04fast-import: add support for new 'alias' commandLibravatar Elijah Newren1-10/+52
fast-export and fast-import have nice --import-marks flags which allow for incremental migrations. However, if there is a mark in fast-export's file of marks without a corresponding mark in the one for fast-import, then we run the risk that fast-export tries to send new objects relative to the mark it knows which fast-import does not, causing fast-import to fail. This arises in practice when there is a filter of some sort running between the fast-export and fast-import processes which prunes some commits programmatically. Provide such a filter with the ability to alias pruned commits to their most recent non-pruned ancestor. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-04fast-import: allow tags to be identified by mark labelsLibravatar Elijah Newren1-1/+2
Mark identifiers are used in fast-export and fast-import to provide a label to refer to earlier content. Blobs are given labels because they need to be referenced in the commits where they first appear with a given filename, and commits are given labels because they can be the parents of other commits. Tags were never given labels, probably because they were viewed as unnecessary, but that presents two problems: 1. It leaves us without a way of referring to previous tags if we want to create a tag of a tag (or higher nestings). 2. It leaves us with no way of recording that a tag has already been imported when using --export-marks and --import-marks. Fix these problems by allowing an optional mark label for tags. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-04fast-import: fix handling of deleted tagsLibravatar Elijah Newren1-0/+27
If our input stream includes a tag which is later deleted, we were not properly deleting it. We did have a step which would delete it, but we left a tag in the tag list noting that it needed to be updated, and the updating of annotated tags occurred AFTER ref deletion. So, when we record that a tag needs to be deleted, also remove it from the list of annotated tags to update. While this has likely been something that has not happened in practice, it will come up more in order to support nested tags. For nested tags, we either need to give temporary names to the intermediate tags and then delete them, or else we need to use the final name for the intermediate tags. If we use the final name for the intermediate tags, then in order to keep the sanity check that someone doesn't try to update the same tag twice, we need to delete the ref after creating the intermediate tag. So, either way nested tags imply the need to delete temporary inner tag references. Helped-by: René Scharfe <l.s.r@web.de> Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-08-27fast-import: duplicate into history rather than passing ownershipLibravatar Jeff King1-3/+1
Fast-import's read_next_command() has somewhat odd memory ownership semantics for the command_buf strbuf. After reading a command, we copy the strbuf's pointer (without duplicating the string) into our cmd_hist array of recent commands. And then when we're about to read a new command, we clear the strbuf by calling strbuf_detach(), dropping ownership from the strbuf (leaving the cmd_hist reference as the remaining owner). This has a few surprising implications: - if the strbuf hasn't been copied into cmd_hist (e.g., because we haven't ready any commands yet), then the strbuf_detach() will leak the resulting string - any modification to command_buf risks invalidating the pointer held by cmd_hist. There doesn't seem to be any way to trigger this currently (since we tend to modify it only by detaching and reading in a new value), but it's subtly dangerous. - any pointers into an input string will remain valid as long as cmd_hist points to them. So in general, you can point into command_buf.buf and call read_next_command() up to 100 times before your string is cycled out and freed, leaving you with a dangling pointer. This makes it easy to miss bugs during testing, as they might trigger only for a sufficiently large commit (e.g., the bug fixed in the previous commit). Instead, let's make a new string to copy the command into the history array, rather than having dual ownership with the old. Then we can drop the strbuf_detach() calls entirely, and just reuse the same buffer within command_buf over and over. We'd normally have to strbuf_reset() it before using it again, but in both cases here we're using strbuf_getline(), which does it automatically for us. This fixes the leak, and it means that even a single call to read_next_command() will invalidate any held pointers, making it easier to find bugs. In fact, we can drop the extra input lines added to the test case by the previous commit, as the unfixed bug would now trigger just from reading the commit message, even without any modified files in the commit. Reported-by: Mike Hommey <mh@glandium.org> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-08-27fast-import: duplicate parsed encoding stringLibravatar Jeff King1-2/+5
We read each line of the fast-import stream into the command_buf strbuf. When reading a commit, we parse a line like "encoding foo" by storing a pointer to "foo", but not making a copy. We may then read an unbounded number of other lines (e.g., one for each modified file in the commit), each of which writes into command_buf. This works out in practice for small cases, because we hand off ownership of the heap buffer from command_buf to the cmd_hist array, and read new commands into a fresh heap buffer. And thus the pointer to "foo" remains valid as long as there aren't so many intermediate lines that we end up dropping the original "encoding" line from the history. But as the test modification shows, if we go over our default of 100 lines, we end up with our encoding string pointing into freed heap memory. This seems to fail reliably by writing garbage into the output, but running under ASan definitely detects this as a use-after-free. We can fix it by duplicating the encoding value, just as we do for other parsed lines (e.g., an author line ends up in parse_ident, which copies it to a new string). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-07-19Merge branch 'nd/tree-walk-with-repo'Libravatar Junio C Hamano1-3/+6
The tree-walk API learned to pass an in-core repository instance throughout more codepaths. * nd/tree-walk-with-repo: t7814: do not generate same commits in different repos Use the right 'struct repository' instead of the_repository match-trees.c: remove the_repo from shift_tree*() tree-walk.c: remove the_repo from get_tree_entry_follow_symlinks() tree-walk.c: remove the_repo from get_tree_entry() tree-walk.c: remove the_repo from fill_tree_descriptor() sha1-file.c: remove the_repo from read_object_with_reference()
2019-07-09Merge branch 'rs/copy-array'Libravatar Junio C Hamano1-1/+1
Code clean-up. * rs/copy-array: use COPY_ARRAY for copying arrays coccinelle: use COPY_ARRAY for copying arrays
2019-06-27sha1-file.c: remove the_repo from read_object_with_reference()Libravatar Nguyễn Thái Ngọc Duy1-3/+6
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-06-17use COPY_ARRAY for copying arraysLibravatar René Scharfe1-1/+1
Convert calls of memcpy(3) to use COPY_ARRAY, which shortens and simplifies the code a bit. Patch generated by Coccinelle and contrib/coccinelle/array.cocci. Signed-off-by: Rene Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-05-14fast-import: support 'encoding' commit headerLibravatar Elijah Newren1-2/+9
Since git supports commit messages with an encoding other than UTF-8, allow fast-import to import such commits. This may be useful for folks who do not want to reencode commit messages from an external system, and may also be useful to achieve reversible history rewrites (e.g. sha1sum <-> sha256sum transitions or subtree work) with git repositories that have used specialized encodings in their commit history. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-04-25Merge branch 'bc/hash-transition-16'Libravatar Junio C Hamano1-26/+40
Conversion from unsigned char[20] to struct object_id continues. * bc/hash-transition-16: (35 commits) gitweb: make hash size independent Git.pm: make hash size independent read-cache: read data in a hash-independent way dir: make untracked cache extension hash size independent builtin/difftool: use parse_oid_hex refspec: make hash size independent archive: convert struct archiver_args to object_id builtin/get-tar-commit-id: make hash size independent get-tar-commit-id: parse comment record hash: add a function to lookup hash algorithm by length remote-curl: make hash size independent http: replace sha1_to_hex http: compute hash of downloaded objects using the_hash_algo http: replace hard-coded constant with the_hash_algo http-walker: replace sha1_to_hex http-push: remove remaining uses of sha1_to_hex http-backend: allow 64-character hex names http-push: convert to use the_hash_algo builtin/pull: make hash-size independent builtin/am: make hash size independent ...
2019-04-01fast-import: fix erroneous handling of get-mark with empty orphan commitsLibravatar Elijah Newren1-6/+2
When get-mark was introduced in commit 28c7b1f7b7b7 ("fast-import: add a get-mark command", 2015-07-01), it followed the precedent of the cat-blob command to be allowed on any line other than in the middle of a data directive; see commit 777f80d7429b ("fast-import: Allow cat-blob requests at arbitrary points in stream", 2010-11-28). It was useful to allow cat-blob directives in the middle of a commit to get more data that would be used in writing the current commit object. get-mark is not similarly useful since fast-import can already use either object id or mark. Further, trying to allow this command anywhere caused parsing bugs. Fix the parsing problems by only allowing get-mark commands to appear when other commands have completed. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-04-01fast-import: only allow cat-blob requests where it makes senseLibravatar Elijah Newren1-6/+13
In commit 777f80d7429b ("fast-import: Allow cat-blob requests at arbitrary points in stream", 2010-11-28), fast-import started allowing cat-blob commands to appear on the start of any line except in the middle of a "data" command. It could be in the middle of various directives that were part of a tag command, or in the middle of checkpoints or progresses (each of which allow an optional second empty newline), or even immediately after the mark command of a blob before the data directive appeared (raising the question of what if it used the mark for the blob that just barely appeared in the stream that we do not yet have the data for). None of these locations make any sense as places to put cat-blob requests. The purpose of this change as stated in that commit message was to [save] frontends from having to loop over everything they want to commit in the next commit and cat-ing the necessary objects in advance. However, that can be achieved by simply allowing cat-blob requests to appear whenever a filemodify directive is allowed. Further, it avoids setting a bad precedent for other commands to follow (e.g. get-mark); a precedent which caused parsing problems in corner cases. Technically, inline filemodify directives add a slight wrinkle in that frontends might want to have cat-blob directives appear after the start of the filemodify and before the data directive contained within it. I think it would have been better to disallow such a case (it would be trivial to use cat-blob before the filemodify instead), but since there is evidence this was used, for backwards compatibility let's support that case too. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-04-01fast-import: check most prominent commands firstLibravatar Elijah Newren1-2/+2
This is not a very important change, and one that I expect to have no performance impact whatsoever, but reading the code bothered me. The parsing of command types in cmd_main() mostly runs in order of most common to least common commands; sure, it's hard to say for sure what the most common are without some type of study, but it seems fairly clear to mark the original four ("blob", "commit", "tag", "reset") as the most prominent. Indeed, the parsing for most other commands were added to later in the list. However, when "ls" was added, it was stuck near the top of the list, with no rationale for that particular location. Move it down to later to appease my Tourette's-like internal twitching that its former location was causing. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-04-01fast-import: replace sha1_to_hexLibravatar brian m. carlson1-2/+2
Replace the uses of sha1_to_hex in this function with hash_to_hex to allow the use of SHA-256 as well. Rename a variable since it is no longer limited to SHA-1. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-04-01fast-import: make hash-size independentLibravatar brian m. carlson1-16/+29
Replace several uses of GIT_SHA1_HEXSZ and 40-based constants with references to the_hash_algo. Update the note handling code here to compute path sizes based on GIT_MAX_RAWSZ as well. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-04-01object-store: rename and expand packed_git's sha1 memberLibravatar brian m. carlson1-8/+9
This member is used to represent the pack checksum of the pack in question. Expand this member to be GIT_MAX_RAWSZ bytes in length so it works with longer hashes and rename it to be "hash" instead of "sha1". This transformation was made with a change to the definition and the following semantic patch: @@ struct packed_git *E1; @@ - E1->sha1 + E1->hash @@ struct packed_git E1; @@ - E1.sha1 + E1.hash Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-01-04Merge branch 'en/fast-export-import'Libravatar Junio C Hamano1-154/+12
Small fixes and features for fast-export and fast-import, mostly on the fast-export side. * en/fast-export-import: fast-export: add a --show-original-ids option to show original names fast-import: remove unmaintained duplicate documentation fast-export: add --reference-excluded-parents option fast-export: ensure we export requested refs fast-export: when using paths, avoid corrupt stream with non-existent mark fast-export: move commit rewriting logic into a function for reuse fast-export: avoid dying when filtering by paths and old tags exist fast-export: use value from correct enum git-fast-export.txt: clarify misleading documentation about rev-list args git-fast-import.txt: fix documentation for --quiet option fast-export: convert sha1 to oid
2018-11-17fast-export: add a --show-original-ids option to show original namesLibravatar Elijah Newren1-0/+12
Knowing the original names (hashes) of commits can sometimes enable post-filtering that would otherwise be difficult or impossible. In particular, the desire to rewrite commit messages which refer to other prior commits (on top of whatever other filtering is being done) is very difficult without knowing the original names of each commit. In addition, knowing the original names (hashes) of blobs can allow filtering by blob-id without requiring re-hashing the content of the blob, and is thus useful as a small optimization. Once we add original ids for both commits and blobs, we may as well add them for tags too for completeness. Perhaps someone will have a use for them. This commit teaches a new --show-original-ids option to fast-export which will make it add a 'original-oid <hash>' line to blob, commits, and tags. It also teaches fast-import to parse (and ignore) such lines. Signed-off-by: Elijah Newren <newren@gmail.com> Acked-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-11-17fast-import: remove unmaintained duplicate documentationLibravatar Elijah Newren1-154/+0
fast-import.c has started with a comment for nine and a half years re-directing the reader to Documentation/git-fast-import.txt for maintained documentation. Instead of leaving the unmaintained documentation in place, just excise it. Signed-off-by: Elijah Newren <newren@gmail.com> Acked-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-11-12Upcast size_t variables to uintmax_t when printingLibravatar Torsten Bögershausen1-2/+2
When printing variables which contain a size, today "unsigned long" is used at many places. In order to be able to change the type from "unsigned long" into size_t some day in the future, we need to have a way to print 64 bit variables on a system that has "unsigned long" defined to be 32 bit, like Win64. Upcast all those variables into uintmax_t before they are printed. This is to prepare for a bigger change, when "unsigned long" will be converted into size_t for variables which may be > 4Gib. Signed-off-by: Torsten Bögershausen <tboegi@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-09-17Merge branch 'jk/cocci'Libravatar Junio C Hamano1-5/+5
spatch transformation to replace boolean uses of !hashcmp() to newly introduced oideq() is added, and applied, to regain performance lost due to support of multiple hash algorithms. * jk/cocci: show_dirstat: simplify same-content check read-cache: use oideq() in ce_compare functions convert hashmap comparison functions to oideq() convert "hashcmp() != 0" to "!hasheq()" convert "oidcmp() != 0" to "!oideq()" convert "hashcmp() == 0" to hasheq() convert "oidcmp() == 0" to oideq() introduce hasheq() and oideq() coccinelle: use <...> for function exclusion
2018-09-17Merge branch 'ds/reachable'Libravatar Junio C Hamano1-0/+1
The code for computing history reachability has been shuffled, obtained a bunch of new tests to cover them, and then being improved. * ds/reachable: commit-reach: correct accidental #include of C file commit-reach: use can_all_from_reach commit-reach: make can_all_from_reach... linear commit-reach: replace ref_newer logic test-reach: test commit_contains test-reach: test can_all_from_reach_with_flags test-reach: test reduce_heads test-reach: test get_merge_bases_many test-reach: test is_descendant_of test-reach: test in_merge_bases test-reach: create new test tool for ref_newer commit-reach: move can_all_from_reach_with_flags upload-pack: generalize commit date cutoff upload-pack: refactor ok_to_give_up() upload-pack: make reachable() more generic commit-reach: move commit_contains from ref-filter commit-reach: move ref_newer from remote.c commit.h: remove method declarations commit-reach: move walk methods from commit.c
2018-08-29convert "oidcmp() != 0" to "!oideq()"Libravatar Jeff King1-2/+2
This is the flip side of the previous two patches: checking for a non-zero oidcmp() can be more strictly expressed as inequality. Like those patches, we write "!= 0" in the coccinelle transformation, which covers by isomorphism the more common: if (oidcmp(E1, E2)) As with the previous two patches, this patch can be achieved almost entirely by running "make coccicheck"; the only differences are manual line-wrap fixes to match the original code. There is one thing to note for anybody replicating this, though: coccinelle 1.0.4 seems to miss the case in builtin/tag.c, even though it's basically the same as all the others. Running with 1.0.7 does catch this, so presumably it's just a coccinelle bug that was fixed in the interim. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-29convert "oidcmp() == 0" to oideq()Libravatar Jeff King1-3/+3
Using the more restrictive oideq() should, in the long run, give the compiler more opportunities to optimize these callsites. For now, this conversion should be a complete noop with respect to the generated code. The result is also perhaps a little more readable, as it avoids the "zero is equal" idiom. Since it's so prevalent in C, I think seasoned programmers tend not to even notice it anymore, but it can sometimes make for awkward double negations (e.g., we can drop a few !!oidcmp() instances here). This patch was generated almost entirely by the included coccinelle patch. This mechanical conversion should be completely safe, because we check explicitly for cases where oidcmp() is compared to 0, which is what oideq() is doing under the hood. Note that we don't have to catch "!oidcmp()" separately; coccinelle's standard isomorphisms make sure the two are treated equivalently. I say "almost" because I did hand-edit the coccinelle output to fix up a few style violations (it mostly keeps the original formatting, but sometimes unwraps long lines). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-20treewide: use get_all_packsLibravatar Derrick Stolee1-2/+2
There are many places in the codebase that want to iterate over all packfiles known to Git. The purposes are wide-ranging, and those that can take advantage of the multi-pack-index already do. So, use get_all_packs() instead of get_packed_git() to be sure we are iterating over all packfiles. Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-02Merge branch 'sb/object-store-lookup'Libravatar Junio C Hamano1-2/+4
lookup_commit_reference() and friends have been updated to find in-core object for a specific in-core repository instance. * sb/object-store-lookup: (32 commits) commit.c: allow lookup_commit_reference to handle arbitrary repositories commit.c: allow lookup_commit_reference_gently to handle arbitrary repositories tag.c: allow deref_tag to handle arbitrary repositories object.c: allow parse_object to handle arbitrary repositories object.c: allow parse_object_buffer to handle arbitrary repositories commit.c: allow get_cached_commit_buffer to handle arbitrary repositories commit.c: allow set_commit_buffer to handle arbitrary repositories commit.c: migrate the commit buffer to the parsed object store commit-slabs: remove realloc counter outside of slab struct commit.c: allow parse_commit_buffer to handle arbitrary repositories tag: allow parse_tag_buffer to handle arbitrary repositories tag: allow lookup_tag to handle arbitrary repositories commit: allow lookup_commit to handle arbitrary repositories tree: allow lookup_tree to handle arbitrary repositories blob: allow lookup_blob to handle arbitrary repositories object: allow lookup_object to handle arbitrary repositories object: allow object_as_type to handle arbitrary repositories tag: add repository argument to deref_tag tag: add repository argument to parse_tag_buffer tag: add repository argument to lookup_tag ...