Merge branch 'tt/bisect-in-c'

More code in "git bisect" has been rewritten in C.

* tt/bisect-in-c:
  bisect--helper: `bisect_start` shell function partially in C
  bisect--helper: `get_terms` & `bisect_terms` shell function in C
  bisect--helper: `bisect_next_check` shell function in C
  bisect--helper: `check_and_set_terms` shell function in C
  wrapper: move is_empty_file() and rename it as is_empty_or_missing_file()
  bisect--helper: `bisect_write` shell function in C
  bisect--helper: `bisect_reset` shell function in C

Author: gitster

builtin/am.c

@@ -34,22 +34,6 @@
 #include "packfile.h"
 #include "repository.h"
 
-/**
- * Returns 1 if the file is empty or does not exist, 0 otherwise.
- */
-static int is_empty_file(const char *filename)
-{
-	struct stat st;
-
-	if (stat(filename, &st) < 0) {
-		if (errno == ENOENT)
-			return 1;
-		die_errno(_("could not stat %s"), filename);
-	}
-
-	return !st.st_size;
-}
-
 /**
  * Returns the length of the first line of msg.
  */
@@ -1220,7 +1204,7 @@ static int parse_mail(struct am_state *state, const char *mail)
 		goto finish;
 	}
 
-	if (is_empty_file(am_path(state, "patch"))) {
+	if (is_empty_or_missing_file(am_path(state, "patch"))) {
 		printf_ln(_("Patch is empty."));
 		die_user_resolve(state);
 	}
@@ -1803,7 +1787,7 @@ static void am_run(struct am_state *state, int resume)
 		resume = 0;
 	}
 
-	if (!is_empty_file(am_path(state, "rewritten"))) {
+	if (!is_empty_or_missing_file(am_path(state, "rewritten"))) {
 		assert(state->rebasing);
 		copy_notes_for_rebase(state);
 		run_post_rewrite_hook(state);