commit-graph: fix type for some write options

The options "max-commits" and "size-multiple" are both supposed to be
positive integers and are documented as such, but we use a signed
integer field to store them. This causes sign comparison warnings in
`split_graph_merge_strategy()` because we end up comparing the option
values with the observed number of commits.

Fix the issue by converting the fields to be unsigned and convert the
options to use `OPT_UNSIGNED()` accordingly. This macro has only been
introduced recently, which might explain why the option values were
signed in the first place.

Signed-off-by: Patrick Steinhardt <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: pks-t

builtin/commit-graph.c

@@ -242,9 +242,9 @@ static int graph_write(int argc, const char **argv, const char *prefix,
 			N_("allow writing an incremental commit-graph file"),
 			PARSE_OPT_OPTARG | PARSE_OPT_NONEG,
 			write_option_parse_split),
-		OPT_INTEGER(0, "max-commits", &write_opts.max_commits,
+		OPT_UNSIGNED(0, "max-commits", &write_opts.max_commits,
 			N_("maximum number of commits in a non-base split commit-graph")),
-		OPT_INTEGER(0, "size-multiple", &write_opts.size_multiple,
+		OPT_UNSIGNED(0, "size-multiple", &write_opts.size_multiple,
 			N_("maximum ratio between two levels of a split commit-graph")),
 		OPT_EXPIRY_DATE(0, "expire-time", &write_opts.expire_time,
 			N_("only expire files older than a given date-time")),

commit-graph.c

@@ -2236,9 +2236,8 @@ static void split_graph_merge_strategy(struct write_commit_graph_context *ctx)
 	uint32_t num_commits;
 	enum commit_graph_split_flags flags = COMMIT_GRAPH_SPLIT_UNSPECIFIED;
 	uint32_t i;
-
-	int max_commits = 0;
-	int size_mult = 2;
+	unsigned max_commits = 0;
+	unsigned size_mult = 2;
 
 	if (ctx->opts) {
 		max_commits = ctx->opts->max_commits;

commit-graph.h

@@ -160,8 +160,8 @@ enum commit_graph_split_flags {
 };
 
 struct commit_graph_opts {
-	int size_multiple;
-	int max_commits;
+	unsigned size_multiple;
+	unsigned max_commits;
 	timestamp_t expire_time;
 	enum commit_graph_split_flags split_flags;
 	int max_new_filters;