treewide: pass strvecs around for setup_revisions_from_strvec()

The previous commit converted callers of setup_revisions() with a strvec
to use the safer and easier _from_strvec() variant.

Let's now convert spots that don't directly have a strvec, but receive
an argc/argv pair that eventually comes from one. We'll instead pass the
strvec down to the point where we call setup_revisions().

That makes these functions slightly less flexible if they were to grow
other callers that don't use strvecs, but this rigidity is buying us
some safety. It is only safe to pass the free_removed_argv_elements
option to setup_revisions() if we know the elements of argv/argc are
allocated on the heap. That isn't communicated in the type system when
we are passed the bare elements. But if we get a strvec, we know that
the elements are allocated strings.

And at any rate, each of these modified functions has only a single
caller (that has a strvec), so the loss of flexibility is unlikely to
ever matter.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

shallow.h

@@ -7,6 +7,7 @@
 #include "strbuf.h"
 
 struct oid_array;
+struct strvec;
 
 void set_alternate_shallow_file(struct repository *r, const char *path, int override);
 int register_shallow(struct repository *r, const struct object_id *oid);
@@ -36,8 +37,8 @@ void rollback_shallow_file(struct repository *r, struct shallow_lock *lk);
 
 struct commit_list *get_shallow_commits(struct object_array *heads,
 					int depth, int shallow_flag, int not_shallow_flag);
-struct commit_list *get_shallow_commits_by_rev_list(
-		int ac, const char **av, int shallow_flag, int not_shallow_flag);
+struct commit_list *get_shallow_commits_by_rev_list(struct strvec *argv,
+						    int shallow_flag, int not_shallow_flag);
 int write_shallow_commits(struct strbuf *out, int use_pack_protocol,
 			  const struct oid_array *extra);