user/sven/git.git/xdiff-interface.h, branch v2.6.1

xdiff: reject files larger than ~1GB

2015-09-28T21:57:23Z

The xdiff code is not prepared to handle extremely large files. It uses "int" in many places, which can overflow if we have a very large number of lines or even bytes in our input files. This can cause us to produce incorrect diffs, with no indication that the output is wrong. Or worse, we may even underallocate a buffer whose size is the result of an overflowing addition. We're much better off to tell the user that we cannot diff or merge such a large file. This patch covers both cases, but in slightly different ways: 1. For merging, we notice the large file and cleanly fall back to a binary merge (which is effectively "we cannot merge this"). 2. For diffing, we make the binary/text distinction much earlier, and in many different places. For this case, we'll use the xdi_diff as our choke point, and reject any diff there before it hits the xdiff code. This means in most cases we'll die() immediately after. That's not ideal, but in practice we shouldn't generally hit this code path unless the user is trying to do something tricky. We already consider files larger than core.bigfilethreshold to be binary, so this code would only kick in when that is circumvented (either by bumping that value, or by using a .gitattribute to mark a file as diffable). In other words, we can avoid being "nice" here, because there is already nice code that tries to do the right thing. We are adding the suspenders to the nice code's belt, so notice when it has been worked around (both to protect the user from malicious inputs, and because it is better to die() than generate bogus output). The maximum size was chosen after experimenting with feeding large files to the xdiff code. It's just under a gigabyte, which leaves room for two obvious cases: - a diff3 merge conflict result on files of maximum size X could be 3*X plus the size of the markers, which would still be only about 3G, which fits in a 32-bit int. - some of the diff code allocates arrays of one int per record. Even if each file consists only of blank lines, then a file smaller than 1G will have fewer than 1G records, and therefore the int array will fit in 4G. Since the limit is arbitrary anyway, I chose to go under a gigabyte, to leave a safety margin (e.g., we would not want to overflow by allocating "(records + 1) * sizeof(int)" or similar. Signed-off-by: Jeff King Signed-off-by: Junio C Hamano

xdiff: remove emit_func() and xdi_diff_hunks()

2012-05-09T21:08:42Z

The functions are unused now, remove them. Signed-off-by: Rene Scharfe Signed-off-by: Junio C Hamano

Merge branch 'maint-1.7.0' into maint

2010-05-04T22:20:47Z

* maint-1.7.0: remove ecb parameter from xdi_diff_outf()

remove ecb parameter from xdi_diff_outf()

2010-05-04T22:19:14Z

xdi_diff_outf() overrides the structure members of its last parameter, ignoring any value that callers pass in. It's no surprise then that all callers pass a pointer to an uninitialized structure. They also don't read it after the call, so the parameter is neither used for input nor for output. Turn it into a local variable of xdi_diff_outf(). Signed-off-by: Rene Scharfe Acked-by: Jeff King Signed-off-by: Junio C Hamano

refactor duplicated fill_mm() in checkout and merge-recursive

2010-02-17T23:11:33Z

The following function is duplicated: fill_mm Move it to xdiff-interface.c and rename it 'read_mmblob', as suggested by Junio C Hamano. Also, change parameters order for consistency with read_mmfile(). Signed-off-by: Michael Lukashov Signed-off-by: Junio C Hamano

userdiff: add xdiff_clear_find_func()

2009-07-02T02:16:37Z

xdiff_set_find_func() is used to set user defined regular expressions for finding function signatures. Add xdiff_clear_find_func(), which frees the memory allocated by the former, making the API complete. Also, use the new function in diff.c (the only call site of xdiff_set_find_func()) to clean up after ourselves. Signed-off-by: Rene Scharfe Signed-off-by: Junio C Hamano

add xdi_diff_hunks() for callers that only need hunk lengths

2008-10-25T19:09:31Z

Based on a patch by Brian Downing, this uses the xdiff emit_func feature to implement xdi_diff_hunks(). It's a function that calls a callback for each hunk of a diff, passing its lengths. Signed-off-by: Rene Scharfe Signed-off-by: Junio C Hamano

Merge branch 'bc/master-diff-hunk-header-fix'

2008-09-29T18:04:20Z

* bc/master-diff-hunk-header-fix: Clarify commit error message for unmerged files Use strchrnul() instead of strchr() plus manual workaround Use remove_path from dir.c instead of own implementation Add remove_path: a function to remove as much as possible of a path git-submodule: Fix "Unable to checkout" for the initial 'update' Clarify how the user can satisfy stash's 'dirty state' check. t4018-diff-funcname: test syntax of builtin xfuncname patterns t4018-diff-funcname: test syntax of builtin xfuncname patterns make "git remote" report multiple URLs diff hunk pattern: fix misconverted "\{" tex macro introducers diff: fix "multiple regexp" semantics to find hunk header comment diff: use extended regexp to find hunk headers diff: use extended regexp to find hunk headers diff.*.xfuncname which uses "extended" regex's for hunk header selection diff.c: associate a flag with each pattern and use it for compiling regex diff.c: return pattern entry pointer rather than just the hunk header pattern Conflicts: builtin-merge-recursive.c t/t7201-co.sh xdiff-interface.h

Merge branch 'jc/better-conflict-resolution'

2008-09-29T17:15:07Z

* jc/better-conflict-resolution: Fix AsciiDoc errors in merge documentation git-merge documentation: describe how conflict is presented checkout --conflict=