[PATCH 1/3] range-diff: drop useless "offset" variable from read_patches()

[Jeff King <peff@peff.net>]

The "offset" variable was was introduced in 44b67cb62b (range-diff:
split lines manually, 2019-07-11), but it has never done anything
useful. We use it to count up the number of bytes we've consumed, but we
never look at the result. It was probably copied accidentally from an
almost-identical loop in apply.c:find_header() (and the point of that
commit was to make use of the parse_git_diff_header() function which
underlies both).

Because the variable was set but not used, most compilers didn't seem to
notice, but the upcoming clang-14 does complain about it, via its
-Wunused-but-set-variable warning.

Signed-off-by: Jeff King <peff@peff.net>
---
The for-loop with an empty initializer and a doubled post-loop operation
is a little funny to see. I didn't see an easy way to make it less ugly
(pushing the line/size initialization into the for() would work, but the
resulting line is awfully long).

 range-diff.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/range-diff.c b/range-diff.c
index e9479794b4..551600c774 100644
--- a/range-diff.c
+++ b/range-diff.c
@@ -49,7 +49,7 @@ static int read_patches(const char *range, struct string_list *list,
 	struct patch_util *util = NULL;
 	int in_header = 1;
 	char *line, *current_filename = NULL;
-	int offset, len;
+	int len;
 	size_t size;
 
 	strvec_pushl(&cp.args, "log", "--no-color", "-p", "--no-merges",
@@ -86,7 +86,7 @@ static int read_patches(const char *range, struct string_list *list,
 
 	line = contents.buf;
 	size = contents.len;
-	for (offset = 0; size > 0; offset += len, size -= len, line += len) {
+	for (; size > 0; size -= len, line += len) {
 		const char *p;
 
 		len = find_end_of_line(line, size);
-- 
2.33.0.rc1.475.g023efe0ae4