git/xdiff, branch v2.26.1

Merge branch 'rs/xdiff-ignore-ws-w-func-context'

2019-12-16T21:08:32Z

The "diff" machinery learned not to lose added/removed blank lines in the context when --ignore-blank-lines and --function-context are used at the same time. * rs/xdiff-ignore-ws-w-func-context: xdiff: unignore changes in function context

xdiff: unignore changes in function context

2019-12-05T17:30:06Z

Changes involving only blank lines are hidden with --ignore-blank-lines, unless they appear in the context lines of other changes. This is handled by xdl_get_hunk() for context added by --inter-hunk-context, -u and -U. Function context for -W and --function-context added by xdl_emit_diff() doesn't pay attention to such ignored changes; it relies fully on xdl_get_hunk() and shows just the post-image of ignored changes appearing in function context. That's inconsistent and confusing. Improve the result of using --ignore-blank-lines and --function-context together by fully showing ignored changes if they happen to fall within function context. Signed-off-by: René Scharfe Signed-off-by: Junio C Hamano

xdiffi: fix typos and touch up comments

2019-10-09T01:58:34Z

Inspired by the thoroughly stale https://github.com/git/git/pull/159, this patch fixes a couple of typos, rewraps and clarifies some comments. Signed-off-by: Johannes Schindelin Signed-off-by: Junio C Hamano

Merge branch 'cb/xdiff-no-system-includes-in-dot-c'

2019-07-31T21:38:56Z

Compilation fix. * cb/xdiff-no-system-includes-in-dot-c: xdiff: remove duplicate headers from xpatience.c xdiff: remove duplicate headers from xhistogram.c xdiff: drop system includes in xutils.c

Merge branch 'jk/xdiff-clamp-funcname-context-index'

2019-07-29T19:39:13Z

The internal diff machinery can be made to read out of bounds while looking for --funcion-context line in a corner case, which has been corrected. * jk/xdiff-clamp-funcname-context-index: xdiff: clamp function context indices in post-image

xdiff: remove duplicate headers from xpatience.c

2019-07-29T04:51:22Z

92b7de93fb (Implement the patience diff algorithm, 2009-01-07) added them but were already part of xinclude.h Signed-off-by: Carlo Marcelo Arenas Belón Signed-off-by: Junio C Hamano

xdiff: remove duplicate headers from xhistogram.c

2019-07-29T04:51:21Z

8c912eea94 ("teach --histogram to diff", 2011-07-12) included them, but were already part of xinclude.h Signed-off-by: Carlo Marcelo Arenas Belón Signed-off-by: Junio C Hamano

xdiff: drop system includes in xutils.c

2019-07-29T04:51:19Z

After b46054b374 ("xdiff: use git-compat-util", 2019-04-11), two system headers added with 6942efcfa9 ("xdiff: load full words in the inner loop of xdl_hash_record", 2012-04-06) to xutils.c are no longer needed and could conflict as shown below from an OpenIndiana build: In file included from xdiff/xinclude.h:26:0, from xdiff/xutils.c:25: ./git-compat-util.h:4:0: warning: "_FILE_OFFSET_BITS" redefined #define _FILE_OFFSET_BITS 64 In file included from /usr/include/limits.h:37:0, from xdiff/xutils.c:23: /usr/include/sys/feature_tests.h:231:0: note: this is the location of the previous definition #define _FILE_OFFSET_BITS 32 Make sure git-compat-util.h is the first header (through xinclude.h) Signed-off-by: Carlo Marcelo Arenas Belón Signed-off-by: Junio C Hamano

xdiff: clamp function context indices in post-image

2019-07-23T21:26:13Z

After finding a function line for --function-context in the pre-image, xdl_emit_diff() calculates the equivalent line in the post-image. It assumes that the lines between changes are the same on both sides. If the option --ignore-blank-lines was also given then this is not necessarily true. Clamp the calculation results for start and end of the function context to prevent out-of-bounds array accesses. Note that this _just_ fixes the case where our mismatch sends us off the beginning of the file. There are likely other cases where our assumption causes us to go to the wrong line within the file. Nobody has developed a test case yet, and the ultimate fix is likely more complicated than this patch. But this at least prevents a segfault in the meantime. Credit for finding the bug goes to "Liu Wei of Tencent Security Xuanwu Lab". Reported-by: 刘炜 Helped-by: René Scharfe Signed-off-by: Jeff King Signed-off-by: Junio C Hamano

xdiff: use xmalloc/xrealloc

2019-04-12T04:34:17Z

Most of xdiff uses a bare malloc() to allocate memory, and returns an error when we get NULL. However, there are a few spots which don't check the return value and may segfault, including at least xdl_merge() and xpatience.c's find_longest_common_sequence(). Let's use xmalloc() everywhere instead, so that we get a graceful die() for these cases, without having to do further auditing. This does mean the existing cases which check errors will now die() instead of returning an error up the stack. But: - that's how the rest of Git behaves already for malloc errors - all of the callers of xdi_diff(), etc, die upon seeing an error So while we might one day want to fully lib-ify the diff code and make it possible to use as part of a long-running process, we're not close to that now. And because we're just tweaking the xdl_malloc() macro here, we're not really moving ourselves any further away from that. We could, for example, simplify some of the functions which handle malloc() errors which can no longer occur. But that would probably be taking us in the wrong direction. This also makes our malloc handling more consistent with the rest of Git, including enforcing GIT_ALLOC_LIMIT and trying to reclaim pack memory when needed. Reported-by: 王健强 Signed-off-by: Jeff King Signed-off-by: Junio C Hamano