Files given on the command line are relative to $cwd

When running "git commit -F file" and "git tag -F file" from a
subdirectory, we should take it as relative to the directory we started
from, not relative to the top-level directory.

This adds a helper function "parse_options_fix_filename()" to make it more
convenient to fix this class of issues.  Ideally, parse_options() should
support a new type of option, "OPT_FILENAME", to do this uniformly, but
this patch is meant to go to 'maint' to fix it minimally.

One thing to note is that value for "commit template file" that comes from
the command line is taken as relative to $cwd just like other parameters,
but when it comes from the configuration varilable 'commit.template', it
is taken as relative to the working tree root as before.  I think this
difference actually is sensible (not that I particularly think
commit.template itself is sensible).

Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 12 insertions, 0 deletions

diff --git a/parse-options.c b/parse-options.c
index f8d52e21f..12c882296 100644
--- a/parse-options.c
+++ b/parse-options.c
@@ -425,3 +425,15 @@ int parse_opt_approxidate_cb(const struct option *opt, const char *arg,
 	*(unsigned long *)(opt->value) = approxidate(arg);
 	return 0;
 }
+
+/*
+ * This should really be OPTION_FILENAME type as a part of
+ * parse_options that take prefix to do this while parsing.
+ */
+extern const char *parse_options_fix_filename(const char *prefix, const char *file)
+{
+	if (!file || !prefix || is_absolute_path(file) || !strcmp("-", file))
+		return file;
+	return prefix_filename(prefix, strlen(prefix), file);
+}
+