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2020-05-14Merge branch 'rs/fsck-duplicate-names-in-trees'Libravatar Junio C Hamano1-2/+70
"git fsck" ensures that the paths recorded in tree objects are sorted and without duplicates, but it failed to notice a case where a blob is followed by entries that sort before a tree with the same name. This has been corrected. * rs/fsck-duplicate-names-in-trees: fsck: report non-consecutive duplicate names in trees
2020-05-11fsck: report non-consecutive duplicate names in treesLibravatar René Scharfe1-2/+70
Tree entries are sorted in path order, meaning that directory names get a slash ('/') appended implicitly. Git fsck checks if trees contains consecutive duplicates, but due to that ordering there can be non-consecutive duplicates as well if one of them is a directory and the other one isn't. Such a tree cannot be fully checked out. Find these duplicates by recording candidate file names on a stack and check candidate directory names against that stack to find matches. Suggested-by: Brandon Williams <bwilliamseng@gmail.com> Original-test-by: Brandon Williams <bwilliamseng@gmail.com> Signed-off-by: René Scharfe <l.s.r@web.de> Reviewed-by: Luke Diamand <luke@diamand.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-28Merge branch 'jk/config-use-size-t'Libravatar Junio C Hamano1-1/+1
The config API made mixed uses of int and size_t types to represent length of various pieces of text it parsed, which has been updated to use the correct type (i.e. size_t) throughout. * jk/config-use-size-t: config: reject parsing of files over INT_MAX config: use size_t to store parsed variable baselen git_config_parse_key(): return baselen as size_t config: drop useless length variable in write_pair() parse_config_key(): return subsection len as size_t remote: drop auto-strlen behavior of make_branch() and make_rewrite()
2020-04-19Git 2.25.4Libravatar Jonathan Nieder1-5/+136
This merges up the security fix from v2.17.5. Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
2020-04-19Git 2.23.3Libravatar Jonathan Nieder1-5/+136
This merges up the security fix from v2.17.5. Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
2020-04-19Git 2.22.4Libravatar Jonathan Nieder1-5/+136
This merges up the security fix from v2.17.5. Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
2020-04-19Git 2.21.3Libravatar Jonathan Nieder1-5/+136
This merges up the security fix from v2.17.5. Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
2020-04-19Git 2.20.4Libravatar Jonathan Nieder1-5/+136
This merges up the security fix from v2.17.5. Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
2020-04-19Git 2.19.5Libravatar Jonathan Nieder1-5/+136
This merges up the security fix from v2.17.5. Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
2020-04-19Git 2.18.4Libravatar Jonathan Nieder1-5/+136
This merges up the security fix from v2.17.5. Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
2020-04-19fsck: reject URL with empty host in .gitmodulesLibravatar Jonathan Nieder1-3/+7
Git's URL parser interprets https:///example.com/repo.git to have no host and a path of "example.com/repo.git". Curl, on the other hand, internally redirects it to https://example.com/repo.git. As a result, until "credential: parse URL without host as empty host, not unset", tricking a user into fetching from such a URL would cause Git to send credentials for another host to example.com. Teach fsck to block and detect .gitmodules files using such a URL to prevent sharing them with Git versions that are not yet protected. A relative URL in a .gitmodules file could also be used to trigger this. The relative URL resolver used for .gitmodules does not normalize sequences of slashes and can follow ".." components out of the path part and to the host part of a URL, meaning that such a relative URL can be used to traverse from a https://foo.example.com/innocent superproject to a https:///attacker.example.com/exploit submodule. Fortunately, redundant extra slashes in .gitmodules are rare, so we can catch this by detecting one after a leading sequence of "./" and "../" components. Helped-by: Jeff King <peff@peff.net> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Reviewed-by: Jeff King <peff@peff.net>
2020-04-19credential: treat URL without scheme as invalidLibravatar Jonathan Nieder1-2/+45
libcurl permits making requests without a URL scheme specified. In this case, it guesses the URL from the hostname, so I can run git ls-remote http::ftp.example.com/path/to/repo and it would make an FTP request. Any user intentionally using such a URL is likely to have made a typo. Unfortunately, credential_from_url is not able to determine the host and protocol in order to determine appropriate credentials to send, and until "credential: refuse to operate when missing host or protocol", this resulted in another host's credentials being leaked to the named host. Teach credential_from_url_gently to consider such a URL to be invalid so that fsck can detect and block gitmodules files with such URLs, allowing server operators to avoid serving them to downstream users running older versions of Git. This also means that when such URLs are passed on the command line, Git will print a clearer error so affected users can switch to the simpler URL that explicitly specifies the host and protocol they intend. One subtlety: .gitmodules files can contain relative URLs, representing a URL relative to the URL they were cloned from. The relative URL resolver used for .gitmodules can follow ".." components out of the path part and past the host part of a URL, meaning that such a relative URL can be used to traverse from a https://foo.example.com/innocent superproject to a https::attacker.example.com/exploit submodule. Fortunately a leading ':' in the first path component after a series of leading './' and '../' components is unlikely to show up in other contexts, so we can catch this by detecting that pattern. Reported-by: Jeff King <peff@peff.net> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Reviewed-by: Jeff King <peff@peff.net>
2020-04-19fsck: convert gitmodules url to URL passed to curlLibravatar Jonathan Nieder1-5/+89
In 07259e74ec1 (fsck: detect gitmodules URLs with embedded newlines, 2020-03-11), git fsck learned to check whether URLs in .gitmodules could be understood by the credential machinery when they are handled by git-remote-curl. However, the check is overbroad: it checks all URLs instead of only URLs that would be passed to git-remote-curl. In principle a git:// or file:/// URL does not need to follow the same conventions as an http:// URL; in particular, git:// and file:// protocols are not succeptible to issues in the credential API because they do not support attaching credentials. In the HTTP case, the URL in .gitmodules does not always match the URL that would be passed to git-remote-curl and the credential machinery: Git's URL syntax allows specifying a remote helper followed by a "::" delimiter and a URL to be passed to it, so that git ls-remote http::https://example.com/repo.git invokes git-remote-http with https://example.com/repo.git as its URL argument. With today's checks, that distinction does not make a difference, but for a check we are about to introduce (for empty URL schemes) it will matter. .gitmodules files also support relative URLs. To ensure coverage for the https based embedded-newline attack, urldecode and check them directly for embedded newlines. Helped-by: Jeff King <peff@peff.net> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Reviewed-by: Jeff King <peff@peff.net>
2020-04-10parse_config_key(): return subsection len as size_tLibravatar Jeff King1-1/+1
We return the length to a subset of a string using an "int *" out-parameter. This is fine most of the time, as we'd expect config keys to be relatively short, but it could behave oddly if we had a gigantic config key. A more appropriate type is size_t. Let's switch over, which lets our callers use size_t as appropriate (they are bound by our type because they must pass the out-parameter as a pointer). This is mostly just a cleanup to make it clear this code handles long strings correctly. In practice, our config parser already chokes on long key names (because of a similar int/size_t mixup!). When doing an int/size_t conversion, we have to be careful that nobody was trying to assign a negative value to the variable. I manually confirmed that for each case here. They tend to just feed the result to xmemdupz() or similar; in a few cases I adjusted the parameter types for helper functions to make sure the size_t is preserved. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-03-17Git 2.25.3Libravatar Junio C Hamano1-1/+15
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-03-17Git 2.23.2Libravatar Junio C Hamano1-1/+15
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-03-17Git 2.22.3Libravatar Junio C Hamano1-1/+15
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-03-17Git 2.21.2Libravatar Junio C Hamano1-1/+15
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-03-17Git 2.20.3Libravatar Junio C Hamano1-1/+15
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-03-17Git 2.19.4Libravatar Junio C Hamano1-1/+15
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-03-17Git 2.18.3Libravatar Junio C Hamano1-1/+15
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-03-12fsck: detect gitmodules URLs with embedded newlinesLibravatar Jeff King1-1/+15
The credential protocol can't handle values with newlines. We already detect and block any such URLs from being used with credential helpers, but let's also add an fsck check to detect and block gitmodules files with such URLs. That will let us notice the problem earlier when transfer.fsckObjects is turned on. And in particular it will prevent bad objects from spreading, which may protect downstream users running older versions of Git. We'll file this under the existing gitmodulesUrl flag, which covers URLs with option injection. There's really no need to distinguish the exact flaw in the URL in this context. Likewise, I've expanded the description of t7416 to cover all types of bogus URLs.
2019-12-09Sync with Git 2.24.1Libravatar Junio C Hamano1-1/+24
2019-12-06Sync with 2.22.2Libravatar Johannes Schindelin1-1/+24
* 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 Schindelin1-1/+24
* 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 Schindelin1-1/+24
* 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 Schindelin1-1/+24
* 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 Schindelin1-1/+24
* 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 Schindelin1-1/+24
* 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 ...
2019-12-06fsck: reject submodule.update = !command in .gitmodulesLibravatar Jonathan Nieder1-0/+7
This allows hosting providers to detect whether they are being used to attack users using malicious 'update = !command' settings in .gitmodules. Since ac1fbbda2013 (submodule: do not copy unknown update mode from .gitmodules, 2013-12-02), in normal cases such settings have been treated as 'update = none', so forbidding them should not produce any collateral damage to legitimate uses. A quick search does not reveal any repositories making use of this construct, either. Reported-by: Joern Schneeweisz <jschneeweisz@gitlab.com> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2019-12-06Sync with 2.16.6Libravatar Johannes Schindelin1-1/+17
* 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 2.14.6Libravatar Johannes Schindelin1-1/+10
* 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 ...
2019-12-05is_ntfs_dotgit(): only verify the leading segmentLibravatar Johannes Schindelin1-1/+10
The config setting `core.protectNTFS` is specifically designed to work not only on Windows, but anywhere, to allow for repositories hosted on, say, Linux servers to be protected against NTFS-specific attack vectors. As a consequence, `is_ntfs_dotgit()` manually splits backslash-separated paths (but does not do the same for paths separated by forward slashes), under the assumption that the backslash might not be a valid directory separator on the _current_ Operating System. However, the two callers, `verify_path()` and `fsck_tree()`, are supposed to feed only individual path segments to the `is_ntfs_dotgit()` function. This causes a lot of duplicate scanning (and very inefficient scanning, too, as the inner loop of `is_ntfs_dotgit()` was optimized for readability rather than for speed. Let's simplify the design of `is_ntfs_dotgit()` by putting the burden of splitting the paths by backslashes as directory separators on the callers of said function. Consequently, the `verify_path()` function, which already splits the path by directory separators, now treats backslashes as directory separators _explicitly_ when `core.protectNTFS` is turned on, even on platforms where the backslash is _not_ a directory separator. Note that we have to repeat some code in `verify_path()`: if the backslash is not a directory separator on the current Operating System, we want to allow file names like `\`, but we _do_ want to disallow paths that are clearly intended to cause harm when the repository is cloned on Windows. The `fsck_tree()` function (the other caller of `is_ntfs_dotgit()`) now needs to look for backslashes in tree entries' names specifically when `core.protectNTFS` is turned on. While it would be tempting to completely disallow backslashes in that case (much like `fsck` reports names containing forward slashes as "full paths"), this would be overzealous: when `core.protectNTFS` is turned on in a non-Windows setup, backslashes are perfectly valid characters in file names while we _still_ want to disallow tree entries that are clearly designed to exploit NTFS-specific behavior. This simplification will make subsequent changes easier to implement, such as turning `core.protectNTFS` on by default (not only on Windows) or protecting against attack vectors involving NTFS Alternate Data Streams. Incidentally, this change allows for catching malicious repositories that contain tree entries of the form `dir\.gitmodules` already on the server side rather than only on the client side (and previously only on Windows): in contrast to `is_ntfs_dotgit()`, the `is_ntfs_dotgitmodules()` function already expects the caller to split the paths by directory separators. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2019-10-28fsck: accept an oid instead of a "struct tree" for fsck_tree()Libravatar Jeff King1-15/+15
We don't actually look at the tree struct in fsck_tree() beyond its oid and type (which is obviously OBJ_TREE). Just taking an oid gives our callers more flexibility to avoid creating a struct, and makes it clear that we are fscking just what is in the buffer, not any pre-parsed bits from the struct. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-28fsck: accept an oid instead of a "struct commit" for fsck_commit()Libravatar Jeff King1-15/+14
We don't actually look at the commit struct in fsck_commit() beyond its oid and type (which is obviously OBJ_COMMIT). Just taking an oid gives our callers more flexibility to avoid creating or parsing a struct, and makes it clear that we are fscking just what is in the buffer, not any pre-parsed bits from the struct. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-28fsck: accept an oid instead of a "struct tag" for fsck_tag()Libravatar Jeff King1-14/+13
We don't actually look at the tag struct in fsck_tag() beyond its oid and type (which is obviously OBJ_TAG). Just taking an oid gives our callers more flexibility to avoid creating or parsing a struct, and makes it clear that we are fscking just what is in the buffer, not any pre-parsed bits from the struct. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-28fsck: rename vague "oid" local variablesLibravatar Jeff King1-4/+4
In fsck_commit() and fsck_tag(), we have local "oid" variables used for parsing parent and tagged-object oids. Let's give these more specific names in preparation for the functions taking an "oid" parameter for the object we're checking. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-28fsck: don't require an object struct in verify_headers()Libravatar Jeff King1-5/+7
We only need the oid and type to pass on to report(). Let's accept the broken-out parameters to give our callers more flexibility. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-28fsck: don't require an object struct for fsck_ident()Libravatar Jeff King1-14/+16
The only thing we do with the struct is pass its oid and type to report(). We can just take those explicitly, which gives our callers more flexibility. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-28fsck: drop blob struct from fsck_finish()Libravatar Jeff King1-14/+4
Since fsck_blob() no longer requires us to have a "struct blob", we don't need to create one. Which also means we don't need to worry about handling the case that lookup_blob() returns NULL (we'll still catch wrongly-identified blobs when we read the actual object contents and type from disk). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-28fsck: accept an oid instead of a "struct blob" for fsck_blob()Libravatar Jeff King1-13/+13
We don't actually need any information from the object struct except its oid (and the type, of course, but that's implicitly OBJ_BLOB). This gives our callers more flexibility to drop the object structs, too. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-28fsck: don't require an object struct for report()Libravatar Jeff King1-59/+69
The report() function really only cares about the oid and type of the object, not the full object struct. Let's convert it to take those two items separately, which gives our callers more flexibility. This makes some already-long lines even longer. I've mostly left them, as our eventual goal is to shrink these down as we continue refactoring (e.g., "&item->object" becomes "&item->object.oid, item->object.type", but will eventually shrink down to "oid, type"). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-28fsck: only require an oid for skiplist functionsLibravatar Jeff King1-4/+5
The skiplist is inherently an oidset, so we don't need a full object struct. Let's take just the oid to give our callers more flexibility. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-28fsck: only provide oid/type in fsck_error callbackLibravatar Jeff King1-4/+7
None of the callbacks actually care about having a "struct object"; they're happy with just the oid and type information. So let's give ourselves more flexibility to avoid having a "struct object" by just passing the broken-down fields. Note that the callback already takes a "type" field for the fsck message type. We'll rename that to "msg_type" (and use "object_type" for the object type) to make the distinction explicit. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-28fsck: use oids rather than objects for object_name APILibravatar Jeff King1-27/+34
We don't actually care about having object structs; we only need to look up decorations by oid. Let's accept this more limited form, which will give our callers more flexibility. Note that the decoration API we rely on uses object structs itself (even though it only looks at their oids). We can solve this by switching to a kh_oid_map (we could also use the hashmap oidmap, but it's more awkward for the simple case of just storing a void pointer). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-28fsck_describe_object(): build on our get_object_name() primitiveLibravatar Jeff King1-4/+1
This isolates the implementation detail of using the decoration code to our put/get functions. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-28fsck: unify object-name codeLibravatar Jeff King1-31/+51
Commit 90cf590f53 (fsck: optionally show more helpful info for broken links, 2016-07-17) added a system for decorating objects with names. The code is split across builtin/fsck.c (which gives the initial names) and fsck.c (which adds to the names as it traverses the object graph). This leads to some duplication, where both sites have near-identical describe_object() functions (the difference being that the one in builtin/fsck.c uses a circular array of buffers to allow multiple calls in a single printf). Let's provide a unified object_name API for fsck. That lets us drop the duplication, as well as making the interface boundaries more clear (which will let us refactor the implementation more in a future patch). We'll leave describe_object() in builtin/fsck.c as a thin wrapper around the new API, as it relies on a static global to make its many callers a bit shorter. We'll also convert the bare add_decoration() calls in builtin/fsck.c to put_object_name(). This fixes two minor bugs: 1. We leak many small strings. add_decoration() has a last-one-wins approach: it updates the decoration to the new string and returns the old one. But we ignore the return value, leaking the old string. This is quite common to trigger, since we look at reflogs: the tip of any ref will be described both by looking at the actual ref, as well as the latest reflog entry. So we'd always end up leaking one of those strings. 2. The last-one-wins approach gives us lousy names. For instance, we first look at all of the refs, and then all of the reflogs. So rather than seeing "refs/heads/master", we're likely to overwrite it with "HEAD@{12345678}". We're generally better off using the first name we find. And indeed, the test in t1450 expects this ugly HEAD@{} name. After this patch, we've switched to using fsck_put_object_name()'s first-one-wins semantics, and we output the more human-friendly "refs/tags/julius" (and the test is updated accordingly). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-28fsck: require an actual buffer for non-blobsLibravatar Jeff King1-42/+9
The fsck_object() function takes in a buffer, but also a "struct object". The rules for using these vary between types: - for a commit, we'll use the provided buffer; if it's NULL, we'll fall back to get_commit_buffer(), which loads from either an in-memory cache or from disk. If the latter fails, we'd die(), which is non-ideal for fsck. - for a tag, a NULL buffer will fall back to loading the object from disk (and failure would lead to an fsck error) - for a tree, we _never_ look at the provided buffer, and always use tree->buffer - for a blob, we usually don't look at the buffer at all, unless it has been marked as a .gitmodule file. In that case we check the buffer given to us, or assume a NULL buffer is a very large blob (and complain about it) This is much more complex than it needs to be. It turns out that nobody ever feeds a NULL buffer that isn't a blob: - git-fsck calls fsck_object() only from fsck_obj(). That in turn is called by one of: - fsck_obj_buffer(), which is a callback to verify_pack(), which unpacks everything except large blobs into a buffer (see pack-check.c, lines 131-141). - fsck_loose(), which hits a BUG() on non-blobs with a NULL buffer (builtin/fsck.c, lines 639-640) And in either case, we'll have just called parse_object_buffer() anyway, which would segfault on a NULL buffer for commits or tags (not for trees, but it would install a NULL tree->buffer which would later cause a segfault) - git-index-pack asserts that the buffer is non-NULL unless the object is a blob (see builtin/index-pack.c, line 832) - git-unpack-objects always writes a non-NULL buffer into its obj_buffer hash, which is then fed to fsck_object(). (There is actually a funny thing here where it does not store blob buffers at all, nor does it call fsck on them; it does check any needed blobs via fsck_finish() though). Let's make the rules simpler, which reduces the amount of code and gives us more flexibility in refactoring the fsck code. The new rules are: - only blobs are allowed to pass a NULL buffer - we always use the provided buffer, never pulling information from the object struct We don't have to adjust any callers, because they were already adhering to these. Note that we do drop a few fsck identifiers for missing tags, but that was all dead code (because nobody passed a NULL tag buffer). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-28fsck: stop checking tag->taggedLibravatar Jeff King1-13/+2
Way back in 92d4c85d24 (fsck-cache: fix SIGSEGV on bad tag object, 2005-05-03), we added an fsck check that the "tagged" field of a tag struct isn't NULL. But that was mainly protecting the printing code for "--tags", and that code wasn't moved along with the check as part of ba002f3b28 (builtin-fsck: move common object checking code to fsck.c, 2008-02-25). It could also serve to detect type mismatch problems (where a tag points to object X as a commit, but really X is a blob), but it couldn't do so reliably (we'd call lookup_commit(X), but it will only notice the problem if we happen to have previously called lookup_blob(X) in the same process). And as of a commit earlier in this series, we'd consider that a parse error and complain about the object even before getting to this point anyway. So let's drop this "tag->tagged" check. It's not helping anything, and getting rid of it makes the function conceptually cleaner, as it really is just checking the buffer we feed it. In fact, we can get rid of our one-line wrapper and just unify fsck_tag() and fsck_tag_buffer(). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-28fsck: stop checking commit->parent countsLibravatar Jeff King1-22/+1
In 4516338243 (builtin-fsck: reports missing parent commits, 2008-02-25), we added code to check that fsck found the same number of parents from parsing the commit itself as we see in the commit struct we got from parse_commit_buffer(). Back then the rationale was that the normal commit parser might skip some bad parents. But earlier in this series, we started treating that reliably as a parsing error, meaning that we'd complain about it before we even hit the code in fsck.c. Let's drop this code, which now makes fsck_commit_buffer() completely independent of any parsed values in the commit struct (that's conceptually cleaner, and also opens up more refactoring options). Note that we can also drop the MISSING_PARENT and MISSING_GRAFT fsck identifiers. This is no loss, as these would not trigger reliably anyway. We'd hit them only when lookup_commit() failed, which occurs only if we happen to have seen the object with another type already in the same process. In most cases, we'd actually run into the problem during the connectivity walk, not here. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>