git/cache.h, branch v2.17.2

Sync with Git 2.16.4

2018-05-22T05:25:26Z

* maint-2.16: Git 2.16.4 Git 2.15.2 Git 2.14.4 Git 2.13.7 verify_path: disallow symlinks in .gitmodules update-index: stat updated files earlier verify_dotfile: mention case-insensitivity in comment verify_path: drop clever fallthrough skip_prefix: add case-insensitive variant is_{hfs,ntfs}_dotgitmodules: add tests is_ntfs_dotgit: match other .git files is_hfs_dotgit: match other .git files is_ntfs_dotgit: use a size_t for traversing string submodule-config: verify submodule names as paths

Sync with Git 2.15.2

2018-05-22T05:18:06Z

* maint-2.15: Git 2.15.2 Git 2.14.4 Git 2.13.7 verify_path: disallow symlinks in .gitmodules update-index: stat updated files earlier verify_dotfile: mention case-insensitivity in comment verify_path: drop clever fallthrough skip_prefix: add case-insensitive variant is_{hfs,ntfs}_dotgitmodules: add tests is_ntfs_dotgit: match other .git files is_hfs_dotgit: match other .git files is_ntfs_dotgit: use a size_t for traversing string submodule-config: verify submodule names as paths

Sync with Git 2.14.4

2018-05-22T05:15:14Z

* maint-2.14: Git 2.14.4 Git 2.13.7 verify_path: disallow symlinks in .gitmodules update-index: stat updated files earlier verify_dotfile: mention case-insensitivity in comment verify_path: drop clever fallthrough skip_prefix: add case-insensitive variant is_{hfs,ntfs}_dotgitmodules: add tests is_ntfs_dotgit: match other .git files is_hfs_dotgit: match other .git files is_ntfs_dotgit: use a size_t for traversing string submodule-config: verify submodule names as paths

Sync with Git 2.13.7

2018-05-22T05:10:49Z

* maint-2.13: Git 2.13.7 verify_path: disallow symlinks in .gitmodules update-index: stat updated files earlier verify_dotfile: mention case-insensitivity in comment verify_path: drop clever fallthrough skip_prefix: add case-insensitive variant is_{hfs,ntfs}_dotgitmodules: add tests is_ntfs_dotgit: match other .git files is_hfs_dotgit: match other .git files is_ntfs_dotgit: use a size_t for traversing string submodule-config: verify submodule names as paths

verify_path: disallow symlinks in .gitmodules

2018-05-22T03:50:11Z

There are a few reasons it's not a good idea to make .gitmodules a symlink, including: 1. It won't be portable to systems without symlinks. 2. It may behave inconsistently, since Git may look at this file in the index or a tree without bothering to resolve any symbolic links. We don't do this _yet_, but the config infrastructure is there and it's planned for the future. With some clever code, we could make (2) work. And some people may not care about (1) if they only work on one platform. But there are a few security reasons to simply disallow it: a. A symlinked .gitmodules file may circumvent any fsck checks of the content. b. Git may read and write from the on-disk file without sanity checking the symlink target. So for example, if you link ".gitmodules" to "../oops" and run "git submodule add", we'll write to the file "oops" outside the repository. Again, both of those are problems that _could_ be solved with sufficient code, but given the complications in (1) and (2), we're better off just outlawing it explicitly. Note the slightly tricky call to verify_path() in update-index's update_one(). There we may not have a mode if we're not updating from the filesystem (e.g., we might just be removing the file). Passing "0" as the mode there works fine; since it's not a symlink, we'll just skip the extra checks. Signed-off-by: Jeff King

is_ntfs_dotgit: match other .git files

2018-05-22T03:50:11Z

When we started to catch NTFS short names that clash with .git, we only looked for GIT~1. This is sufficient because we only ever clone into an empty directory, so .git is guaranteed to be the first subdirectory or file in that directory. However, even with a fresh clone, .gitmodules is *not* necessarily the first file to be written that would want the NTFS short name GITMOD~1: a malicious repository can add .gitmodul0000 and friends, which sorts before `.gitmodules` and is therefore checked out *first*. For that reason, we have to test not only for ~1 short names, but for others, too. It's hard to just adapt the existing checks in is_ntfs_dotgit(): since Windows 2000 (i.e., in all Windows versions still supported by Git), NTFS short names are only generated in the ~ form up to number 4. After that, a *different* prefix is used, calculated from the long file name using an undocumented, but stable algorithm. For example, the short name of .gitmodules would be GITMOD~1, but if it is taken, and all of ~2, ~3 and ~4 are taken, too, the short name GI7EBA~1 will be used. From there, collisions are handled by incrementing the number, shortening the prefix as needed (until ~9999999 is reached, in which case NTFS will not allow the file to be created). We'd also want to handle .gitignore and .gitattributes, which suffer from a similar problem, using the fall-back short names GI250A~1 and GI7D29~1, respectively. To accommodate for that, we could reimplement the hashing algorithm, but it is just safer and simpler to provide the known prefixes. This algorithm has been reverse-engineered and described at https://usn.pw/blog/gen/2015/06/09/filenames/, which is defunct but still available via https://web.archive.org/. These can be recomputed by running the following Perl script: -- snip -- use warnings; use strict; sub compute_short_name_hash ($) { my $checksum = 0; foreach (split('', $_[0])) { $checksum = ($checksum * 0x25 + ord($_)) & 0xffff; } $checksum = ($checksum * 314159269) & 0xffffffff; $checksum = 1 + (~$checksum & 0x7fffffff) if ($checksum & 0x80000000); $checksum -= (($checksum * 1152921497) >> 60) * 1000000007; return scalar reverse sprintf("%x", $checksum & 0xffff); } print compute_short_name_hash($ARGV[0]); -- snap -- E.g., running that with the argument ".gitignore" will result in "250a" (which then becomes "gi250a" in the code). Signed-off-by: Johannes Schindelin Signed-off-by: Jeff King

Merge branch 'tg/split-index-fixes' into maint

2018-03-22T21:24:10Z

The split-index mode had a few corner case bugs fixed. * tg/split-index-fixes: travis: run tests with GIT_TEST_SPLIT_INDEX split-index: don't write cache tree with null oid entries read-cache: fix reading the shared index for other repos

Merge branch 'ma/skip-writing-unchanged-index'

2018-03-21T18:30:10Z

Internal API clean-up to allow write_locked_index() optionally skip writing the in-core index when it is not modified. * ma/skip-writing-unchanged-index: write_locked_index(): add flag to avoid writing unchanged index

Merge branch 'bw/c-plus-plus'

2018-03-06T22:54:07Z

Avoid using identifiers that clash with C++ keywords. Even though it is not a goal to compile Git with C++ compilers, changes like this help use of code analysis tools that targets C++ on our codebase. * bw/c-plus-plus: (37 commits) replace: rename 'new' variables trailer: rename 'template' variables tempfile: rename 'template' variables wrapper: rename 'template' variables environment: rename 'namespace' variables diff: rename 'template' variables environment: rename 'template' variables init-db: rename 'template' variables unpack-trees: rename 'new' variables trailer: rename 'new' variables submodule: rename 'new' variables split-index: rename 'new' variables remote: rename 'new' variables ref-filter: rename 'new' variables read-cache: rename 'new' variables line-log: rename 'new' variables imap-send: rename 'new' variables http: rename 'new' variables entry: rename 'new' variables diffcore-delta: rename 'new' variables ...

write_locked_index(): add flag to avoid writing unchanged index

2018-03-01T21:28:01Z

We have several callers like if (active_cache_changed && write_locked_index(...)) handle_error(); rollback_lock_file(...); where the final rollback is needed because "!active_cache_changed" shortcuts the if-expression. There are also a few variants of this, including some if-else constructs that make it more clear when the explicit rollback is really needed. Teach `write_locked_index()` to take a new flag SKIP_IF_UNCHANGED and simplify the callers. Leave the most complicated of the callers (in builtin/update-index.c) unchanged. Rewriting it to use this new flag would end up duplicating logic. We could have made the new flag behave the other way round ("FORCE_WRITE"), but that could break existing users behind their backs. Let's take the more conservative approach. We can still migrate existing callers to use our new flag. Later we might even be able to flip the default, possibly without entirely ignoring the risk to in-flight or out-of-tree topics. Suggested-by: Jeff King Signed-off-by: Martin Ågren Signed-off-by: Junio C Hamano