This patch series adds a new diff option that enables ignoring changes
whose all lines (changed, removed, and added) match a given regular
expression. This is similar to the -I/--ignore-matching-lines option in
standalone diff utilities and can be used e.g. to ignore changes which
only affect code comments or to look for unrelated changes in commits
containing a large number of automatically applied modifications (e.g. a
tree-wide string replacement). The difference between -G/-S and the new
-I option is that the latter filters output on a per-change basis.
Changes from v3:
- Do not release the memory allocated in diff_opt_ignore_regex() after
all as the free() calls added in v2 were triggering use-after-free
errors when the diff machinery was invoked multiple times throughout
the lifetime of a single Git command (e.g. by "git log -p").
- Further test improvements: split various -I<regex> checks into
multiple tests; add a check for "git log -p -I<regex>" to trigger
the issue mentioned above; avoid using --no-index.
Changes from v2:
- Add a long option for -I (--ignore-matching-lines) as it is
commonplace in standalone diff utilities. Update documentation and
commit log messages accordingly.
- Use xmalloc() instead of xcalloc() for allocating regex_t
structures in diff_opt_ignore_regex().
- Ensure the memory allocated in diff_opt_ignore_regex() gets
released.
- Use "return error(...)" instead of die() in the -I option callback.
Make sure the error message is localizable.
- Drastically reduce the number of -I<regex> tests due to excessive
run time of t/t4069-diff-ignore-regex.sh from v1/v2 on some
platforms (notably Windows). Use a tweaked version of a test
suggested by Johannes Schindelin (thanks!). Squash patch 3 into
patch 2.
- Replace "see Documentation/diff-options.txt" with "-I<regex>" in the
comments for the added structure fields, in order to make these
comments more useful.
Changes from v1:
- Add a new preliminary cleanup patch which ensures xpparam_t
structures are always zero-initialized. (This was a prerequisite
for the next change below.)
- Do not add a new 'xdl_opts' flag to check whether -I was used;
instead, just check whether the array of regular expressions to
match against is non-NULL.
- Enable the -I option to be used multiple times. As a consequence of
this, regular expressions are now "pre-compiled" in the option's
callback (and passed around as an array of regex_t structures)
rather than deep down in xdiff code. Add test cases exercising use
of multiple -I options in the same git invocation. Update
documentation accordingly.
- Rename xdl_mark_ignorable() to xdl_mark_ignorable_lines(), to
indicate that it is logically a "sibling" of
xdl_mark_ignorable_regex() rather than its "parent".
- Optimize xdl_mark_ignorable_regex() by making it immediately skip
changes already marked as ignored by xdl_mark_ignorable_lines().
- Fix coding style issue in the prototype part of the definition of
xdl_mark_ignorable_regex().
- Add "/* see Documentation/diff-options.txt */" comments for the
fields added to struct diff_options and xpparam_t, mimicking the
comments used for 'anchors', 'anchors_nr', and 'anchors_alloc'.
- Revise commit log messages to reflect all of the above.
Michał Kępień (2):
merge-base, xdiff: zero out xpparam_t structures
diff: add -I<regex> that ignores matching changes
Documentation/diff-options.txt | 5 ++
builtin/merge-tree.c | 1 +
diff.c | 23 +++++
diff.h | 4 +
t/t4013-diff-various.sh | 41 +++++++++
t/t4013/diff.log_-IA_-IB_-I1_-I2_-p_master | 99 ++++++++++++++++++++++
xdiff/xdiff.h | 4 +
xdiff/xdiffi.c | 47 +++++++++-
xdiff/xhistogram.c | 2 +
xdiff/xpatience.c | 2 +
10 files changed, 226 insertions(+), 2 deletions(-)
create mode 100644 t/t4013/diff.log_-IA_-IB_-I1_-I2_-p_master
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2.28.0
