On Wed, Sep 25, 2019 at 01:39:19PM -0700, Denton Liu wrote: > Hi Elijah, > > I ran into a segfault on MacOS. I managed to bisect it down to > 404ebceda0 (dir: also check directories for matching pathspecs, > 2019-09-17), which should be the patch in the parent thread. The test > case below works fine without this patch applied but segfaults once it > is applied. > > #!/bin/sh > > git worktree add testdir > git -C testdir checkout master > git -C testdir fetch https://github.com/git/git.git todo > bin-wrappers/git -C testdir checkout FETCH_HEAD # segfault here > > Note that the worktree part isn't necessary to reproduce the problem but > I didn't want my files to be constantly refreshed, triggering a rebuild > each time. > > I also managed to get this backtrace from running lldb at the segfault > but it is based on the latest "jch" commit, 1cc52d20df (Merge branch > 'jt/merge-recursive-symlink-is-not-a-dir-in-way' into jch, 2019-09-20). > > * thread #1, queue = 'com.apple.main-thread', stop reason = > EXC_BAD_ACCESS (code=1, address=0x8) > * frame #0: 0x00000001000f63a0 > git`do_match_pathspec(istate=0x0000000100299940, ps=0x000000010200aa80, > name="Gitweb/static/js/lib/", namelen=21, prefix=0, seen=0x0000000000000000, > flags=0) at dir.c:420:2 [opt] > frame #1: 0x00000001000f632c > git`match_pathspec(istate=0x0000000100299940, ps=0x0000000000000000, > name="Gitweb/static/js/lib/", namelen=21, prefix=0, seen=0x0000000000000000, > is_dir=0) at dir.c:490:13 [opt] > frame #2: 0x00000001000f8315 > git`read_directory_recursive(dir=0x00007ffeefbfe278, > istate=0x0000000100299940, base=<unavailable>, baselen=17, > untracked=<unavailable>, check_only=0, stop_at_first_file=0, > pathspec=0x0000000000000000) at dir.c:1990:9 [opt] > frame #3: 0x00000001000f82e9 > git`read_directory_recursive(dir=0x00007ffeefbfe278, > istate=0x0000000100299940, base=<unavailable>, baselen=14, > untracked=<unavailable>, check_only=0, stop_at_first_file=0, > pathspec=0x0000000000000000) at dir.c:1984:5 [opt] > frame #4: 0x00000001000f82e9 > git`read_directory_recursive(dir=0x00007ffeefbfe278, > istate=0x0000000100299940, base=<unavailable>, baselen=7, > untracked=<unavailable>, check_only=0, stop_at_first_file=0, > pathspec=0x0000000000000000) at dir.c:1984:5 [opt] > frame #5: 0x00000001000f60d1 > git`read_directory(dir=0x00007ffeefbfe278, istate=0x0000000100299940, > path="Gitweb/", len=7, pathspec=0x0000000000000000) at dir.c:2298:3 [opt] > frame #6: 0x00000001001bded1 > git`verify_clean_subdirectory(ce=<unavailable>, o=0x00007ffeefbfe8c0) at > unpack-trees.c:1846:6 [opt] > frame #7: 0x00000001001bdc1d > git`check_ok_to_remove(name="Gitweb", len=6, dtype=4, ce=0x0000000103e70de0, > st=0x00007ffeefbfe438, error_type=ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN, > o=0x00007ffeefbfe8c0) at unpack-trees.c:1901:7 [opt]
That 'name="Gitweb" parameter caught my eye. origin/todo contains a 'Gitweb' file, with upper case 'G', while master contains a 'gitweb' directory, with lower case 'g'. Could it be that case (in)sensitivity plays a crucial rule in triggering the segfault? FWIW I could reproduce it following Denton's description on Travis CI's macOS VM with the debug shell access, and it uses case insensitive file system.
