split_commit_in_progress(): simplify & fix memory leak

This function did a whole lot of unnecessary work, such as reading in
four files just to figure out that, oh, hey, we do not need to look at
them after all because the HEAD is not detached.

Simplify the entire function to return early when possible, to read in
the files only when necessary, and to release the allocated memory
always (there was a leak, reported via Coverity, where we failed to
release the allocated strings if the HEAD is not detached).

Signed-off-by: Johannes Schindelin <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: dscho

wt-status.c

@@ -1082,29 +1082,29 @@ static char *read_line_from_git_path(const char *filename)
 static int split_commit_in_progress(struct wt_status *s)
 {
 	int split_in_progress = 0;
-	char *head = read_line_from_git_path("HEAD");
-	char *orig_head = read_line_from_git_path("ORIG_HEAD");
-	char *rebase_amend = read_line_from_git_path("rebase-merge/amend");
-	char *rebase_orig_head = read_line_from_git_path("rebase-merge/orig-head");
+	char *head, *orig_head, *rebase_amend, *rebase_orig_head;
 
-	if (!head || !orig_head || !rebase_amend || !rebase_orig_head ||
+	if ((!s->amend && !s->nowarn && !s->workdir_dirty) ||
 	    !s->branch || strcmp(s->branch, "HEAD"))
-		return split_in_progress;
+		return 0;
 
-	if (!strcmp(rebase_amend, rebase_orig_head)) {
-		if (strcmp(head, rebase_amend))
-			split_in_progress = 1;
-	} else if (strcmp(orig_head, rebase_orig_head)) {
-		split_in_progress = 1;
-	}
+	head = read_line_from_git_path("HEAD");
+	orig_head = read_line_from_git_path("ORIG_HEAD");
+	rebase_amend = read_line_from_git_path("rebase-merge/amend");
+	rebase_orig_head = read_line_from_git_path("rebase-merge/orig-head");
 
-	if (!s->amend && !s->nowarn && !s->workdir_dirty)
-		split_in_progress = 0;
+	if (!head || !orig_head || !rebase_amend || !rebase_orig_head)
+		; /* fall through, no split in progress */
+	else if (!strcmp(rebase_amend, rebase_orig_head))
+		split_in_progress = !!strcmp(head, rebase_amend);
+	else if (strcmp(orig_head, rebase_orig_head))
+		split_in_progress = 1;
 
 	free(head);
 	free(orig_head);
 	free(rebase_amend);
 	free(rebase_orig_head);
+
 	return split_in_progress;
 }