I just had the need to find out upstream commits corresponding to a handful
of backported commits, and most importantly, identify upstream commits
touching a given file that had not yet been backported.

This new mode helped me identify them.

Changes since v1:

 * The command-line parameter parsing now avoids duplicating code as much as
   possible.
 * This also fixes a bug where git range-diff <incorrect-symmetric-range> --
   <pathspec> was mistaken for using the three-revision stanza.
 * Consistent validation of the command-line arguments has been extracted
   into its own patch.
 * Sadly, these changes make the overall diff much larger. I hope that the
   readability is worth that price.

Johannes Schindelin (3):
  range-diff: reorder argument handling
  range-diff: consistently validate the arguments
  range-diff: optionally accept pathspecs

 Documentation/git-range-diff.txt |   4 ++
 builtin/range-diff.c             | 101 +++++++++++++++++++++++--------
 range-diff.c                     |   2 +-
 t/t3206-range-diff.sh            |  13 +++-
 4 files changed, 94 insertions(+), 26 deletions(-)

base-commit: 795ea8776befc95ea2becd8020c7a284677b4161

Submitted-As: https://lore.kernel.org/git/pull.1335.v2.git.1661506770.gitgitgadget@gmail.com
In-Reply-To: https://lore.kernel.org/git/pull.1335.git.1661258122.gitgitgadget@gmail.com