diff mbox series

[v4,07/27] diff: cast string constant in `fill_textconv()`

Message ID 6e631a9ea46aa563d197f4a057698a0af53ad50f.1717504517.git.ps@pks.im (mailing list archive)
State Superseded
Headers show
Series Compile with `-Wwrite-strings` | expand

Commit Message

Patrick Steinhardt June 4, 2024, 12:37 p.m. UTC 
The `fill_textconv()` function is responsible for converting an input
file with a textconv driver, which is then passed to the caller. Weirdly
though, the function also handles the case where there is no textconv
driver at all. In that case, it will return either the contents of the
populated filespec, or an empty string if the filespec is invalid.

These two cases have differing memory ownership semantics. When there is
a textconv driver, then the result is an allocated string. Otherwise,
the result is either a string constant or owned by the filespec struct.
All callers are in fact aware of this weirdness and only end up freeing
the output buffer when they had a textconv driver.

Ideally, we'd split up this interface to only perform the conversion via
the textconv driver, and BUG in case the caller didn't provide one. This
would make memory ownership semantics much more straight forward. For
now though, let's simply cast the empty string constant to `char *` to
avoid a warning with `-Wwrite-strings`. This is equivalent to the same
cast that we already have in `fill_mmfile()`.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
---
 diff.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/diff.c b/diff.c
index ffd867ef6c..cecda216cf 100644
--- a/diff.c
+++ b/diff.c
@@ -7235,7 +7235,7 @@  size_t fill_textconv(struct repository *r,
 
 	if (!driver) {
 		if (!DIFF_FILE_VALID(df)) {
-			*outbuf = "";
+			*outbuf = (char *) "";
 			return 0;
 		}
 		if (diff_populate_filespec(r, df, NULL))