"Johannes Schindelin via GitGitGadget" <gitgitgadget@xxxxxxxxx> writes: > From: Johannes Schindelin <johannes.schindelin@xxxxxx> > > When running an external diff from, say, a diff tool, it is safe to > assume that we want to write the files in question. On Windows, that > means that there cannot be any other process holding an open handle to > said files. Please add "It is not enough to close the file descriptor; having a region that is still mmapped keeps the file busy" or something like that at the end. > So let's make sure that `git diff` itself is not holding any open handle > to the files in question. > > This fixes https://github.com/git-for-windows/git/issues/1315 > > Signed-off-by: Johannes Schindelin <johannes.schindelin@xxxxxx> > --- > diff.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/diff.c b/diff.c > index 4d3cf83a27..0afb76bbca 100644 > --- a/diff.c > +++ b/diff.c > @@ -4206,6 +4206,10 @@ static void run_external_diff(const char *pgm, > argv_array_pushf(&env, "GIT_DIFF_PATH_COUNTER=%d", ++o->diff_path_counter); > argv_array_pushf(&env, "GIT_DIFF_PATH_TOTAL=%d", q->nr); > > + if (one && one->should_munmap) > + diff_free_filespec_data(one); > + if (two && two->should_munmap) > + diff_free_filespec_data(two); I wondered if a single diff_filespec instance can be used in two diff_filepair instances (e.g. file A is in-place modified and also used to create file C), and if so after showing the diff for file A, we have problems with showing file C. But I do not think it should pose a problem, as "free data after comparing a pair" is what we do for the in-core codepath in builtin_diff(). We can lose the NULL-ness test for one and two if these "free the resource once we no longer need it" is done inside "if (one && two)". After all, once add_external_diff_name()[*1*] does its thing, we do not need the data for these diff_filespec instances, right? Also, just like builtin_diff() unconditionally frees the resources held by diff_filespec instances, shouldn't this function do so, even the ones that are not marked with should_munmap? > if (run_command_v_opt_cd_env(argv.argv, RUN_USING_SHELL, NULL, env.argv)) > die(_("external diff died, stopping at %s"), name);
