commit-reach: fix type of min_commit_date

The `can_all_from_reach_with_flag()` function accepts a parameter that
allows callers to cut off traversal at a specified commit date. This
parameter is of type `time_t`, which is a signed type, while we end up
comparing it to a commit's `date` field, which is of the unsigned type
`timestamp_t`.

Fix the parameter to be of type `timestamp_t`. There is only a single
caller in "upload-pack.c" that sets this parameter, and that caller
knows to pass in a `timestamp_t` already.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: pks-t

commit-reach.c

@@ -780,7 +780,7 @@ int commit_contains(struct ref_filter *filter, struct commit *commit,
 int can_all_from_reach_with_flag(struct object_array *from,
 				 unsigned int with_flag,
 				 unsigned int assign_flag,
-				 time_t min_commit_date,
+				 timestamp_t min_commit_date,
 				 timestamp_t min_generation)
 {
 	struct commit **list = NULL;
@@ -883,9 +883,9 @@ int can_all_from_reach(struct commit_list *from, struct commit_list *to,
 		       int cutoff_by_min_date)
 {
 	struct object_array from_objs = OBJECT_ARRAY_INIT;
-	time_t min_commit_date = cutoff_by_min_date ? from->item->date : 0;
 	struct commit_list *from_iter = from, *to_iter = to;
 	int result;
+	timestamp_t min_commit_date = cutoff_by_min_date ? from->item->date : 0;
 	timestamp_t min_generation = GENERATION_NUMBER_INFINITY;
 
 	while (from_iter) {

commit-reach.h

@@ -81,7 +81,7 @@ int commit_contains(struct ref_filter *filter, struct commit *commit,
 int can_all_from_reach_with_flag(struct object_array *from,
 				 unsigned int with_flag,
 				 unsigned int assign_flag,
-				 time_t min_commit_date,
+				 timestamp_t min_commit_date,
 				 timestamp_t min_generation);
 int can_all_from_reach(struct commit_list *from, struct commit_list *to,
 		       int commit_date_cutoff);