[PATCH v4 0/8] Directory traversal bugs

This series documents multiple fill_directory() bugs, and fixes the one that is new to 2.24.0 coming from en/clean-nested-with-ignored-topic, the rest having been around in versions of git going back up to a decade.

Changes since v2 (v3 was sent earlier, but this series is closer to v2):

 * protected access to d_type with a !defined(NO_D_TYPE_IN_DIRENT) and made
   sure to allocate a dirent on the heap with some extra space for d_name
   rather than allocating the dirent on the stack.

Elijah Newren (8):
  t3011: demonstrate directory traversal failures
  Revert "dir.c: make 'git-status --ignored' work within leading
    directories"
  dir: remove stray quote character in comment
  dir: exit before wildcard fall-through if there is no wildcard
  dir: break part of read_directory_recursive() out for reuse
  dir: fix checks on common prefix directory
  dir: synchronize treat_leading_path() and read_directory_recursive()
  dir: consolidate similar code in treat_directory()

 dir.c                                         | 177 +++++++++++----
 ...common-prefixes-and-directory-traversal.sh | 209 ++++++++++++++++++
 t/t7061-wtstatus-ignore.sh                    |   9 +-
 3 files changed, 344 insertions(+), 51 deletions(-)
 create mode 100755 t/t3011-common-prefixes-and-directory-traversal.sh

base-commit: da72936f544fec5a335e66432610e4cef4430991
Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-git-676%2Fnewren%2Fls-files-bug-v4
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-git-676/newren/ls-files-bug-v4
Pull-Request: https://github.com/git/git/pull/676

Range-diff vs v3:

 1:  61d303d8bd ! 1:  6d659b2302 t3011: demonstrate directory traversal failures
     @@ -14,18 +14,6 @@
          of the en/clean-nested-with-ignored-topic); the other 5 also failed
          under git-2.23.0 and earlier.
      
     -    The old failing tests can be traced down to the common prefix
     -    optimization in dir.c handling paths differently than
     -    read_directory_recursive() and treat_path() would, due to incomplete
     -    duplication of logic into treat_leading_path() and having that
     -    function call treat_one_path() rather than treat_path().  Fixing
     -    that problem would require restructuring treat_path() and its full
     -    call hierarchy to stop taking a dirent; see
     -       https://lore.kernel.org/git/xmqqzhfshsk2.fsf@gitster-ct.c.googlers.com/
     -    and the thread surrounding it for details.
     -
     -    For now, simply document the breakages.
     -
          Signed-off-by: Elijah Newren <newren@gmail.com>
      
       diff --git a/t/t3011-common-prefixes-and-directory-traversal.sh b/t/t3011-common-prefixes-and-directory-traversal.sh
 -:  ---------- > 2:  79f2b56174 Revert "dir.c: make 'git-status --ignored' work within leading directories"
 2:  49b0b628db = 3:  d6f858cab1 dir: remove stray quote character in comment
 3:  47814640e4 = 4:  8d2d98eec3 dir: exit before wildcard fall-through if there is no wildcard
 -:  ---------- > 5:  d2f5623bd7 dir: break part of read_directory_recursive() out for reuse
 -:  ---------- > 6:  1f3978aa46 dir: fix checks on common prefix directory
 -:  ---------- > 7:  542c6e5792 dir: synchronize treat_leading_path() and read_directory_recursive()
 -:  ---------- > 8:  31079dc1cf dir: consolidate similar code in treat_directory()