line-log: fix several memory leaks

As described in "line-log.c" itself, the code is "leaking like a sieve".
These leaks are all of rather trivial nature, so this commit plugs them
without going too much into details for each of those leaks.

The leaks are hit by t4211, but plugging them alone does not make the
full test suite pass. The remaining leaks are unrelated to the line-log
subsystem.

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

Author: pks-t

line-log.c

@@ -248,8 +248,10 @@ static void line_log_data_init(struct line_log_data *r)
 static void line_log_data_clear(struct line_log_data *r)
 {
 	range_set_release(&r->ranges);
+	free(r->path);
 	if (r->pair)
 		diff_free_filepair(r->pair);
+	diff_ranges_release(&r->diff);
 }
 
 static void free_line_log_data(struct line_log_data *r)
@@ -571,7 +573,8 @@ parse_lines(struct repository *r, struct commit *commit,
 	struct line_log_data *p;
 
 	for_each_string_list_item(item, args) {
-		const char *name_part, *range_part;
+		const char *name_part;
+		char *range_part;
 		char *full_name;
 		struct diff_filespec *spec;
 		long begin = 0, end = 0;
@@ -615,6 +618,7 @@ parse_lines(struct repository *r, struct commit *commit,
 
 		free_filespec(spec);
 		FREE_AND_NULL(ends);
+		free(range_part);
 	}
 
 	for (p = ranges; p; p = p->next)
@@ -760,15 +764,13 @@ static void parse_pathspec_from_ranges(struct pathspec *pathspec,
 {
 	struct line_log_data *r;
 	struct strvec array = STRVEC_INIT;
-	const char **paths;
 
 	for (r = range; r; r = r->next)
 		strvec_push(&array, r->path);
-	paths = strvec_detach(&array);
 
-	parse_pathspec(pathspec, 0, PATHSPEC_PREFER_FULL, "", paths);
-	/* strings are now owned by pathspec */
-	free(paths);
+	parse_pathspec(pathspec, 0, PATHSPEC_PREFER_FULL, "", array.v);
+
+	strvec_clear(&array);
 }
 
 void line_log_init(struct rev_info *rev, const char *prefix, struct string_list *args)
@@ -781,6 +783,8 @@ void line_log_init(struct rev_info *rev, const char *prefix, struct string_list
 	add_line_range(rev, commit, range);
 
 	parse_pathspec_from_ranges(&rev->diffopt.pathspec, range);
+
+	free_line_log_data(range);
 }
 
 static void move_diff_queue(struct diff_queue_struct *dst,
@@ -1131,10 +1135,18 @@ static int process_all_files(struct line_log_data **range_out,
 			while (rg && strcmp(rg->path, pair->two->path))
 				rg = rg->next;
 			assert(rg);
+			if (rg->pair)
+				diff_free_filepair(rg->pair);
 			rg->pair = diff_filepair_dup(queue->queue[i]);
+			diff_ranges_release(&rg->diff);
 			memcpy(&rg->diff, pairdiff, sizeof(struct diff_ranges));
+			FREE_AND_NULL(pairdiff);
+		}
+
+		if (pairdiff) {
+			diff_ranges_release(pairdiff);
+			free(pairdiff);
 		}
-		free(pairdiff);
 	}
 
 	return changed;
@@ -1212,12 +1224,13 @@ static int process_ranges_merge_commit(struct rev_info *rev, struct commit *comm
 	struct commit_list *p;
 	int i;
 	int nparents = commit_list_count(commit->parents);
+	int ret;
 
 	if (nparents > 1 && rev->first_parent_only)
 		nparents = 1;
 
 	ALLOC_ARRAY(diffqueues, nparents);
-	ALLOC_ARRAY(cand, nparents);
+	CALLOC_ARRAY(cand, nparents);
 	ALLOC_ARRAY(parents, nparents);
 
 	p = commit->parents;
@@ -1229,40 +1242,43 @@ static int process_ranges_merge_commit(struct rev_info *rev, struct commit *comm
 
 	for (i = 0; i < nparents; i++) {
 		int changed;
-		cand[i] = NULL;
 		changed = process_all_files(&cand[i], rev, &diffqueues[i], range);
 		if (!changed) {
 			/*
 			 * This parent can take all the blame, so we
 			 * don't follow any other path in history
 			 */
 			add_line_range(rev, parents[i], cand[i]);
-			clear_commit_line_range(rev, commit);
 			commit_list_append(parents[i], &commit->parents);
-			free(parents);
-			free(cand);
-			free_diffqueues(nparents, diffqueues);
-			/* NEEDSWORK leaking like a sieve */
-			return 0;
+
+			ret = 0;
+			goto out;
 		}
 	}
 
 	/*
 	 * No single parent took the blame.  We add the candidates
 	 * from the above loop to the parents.
 	 */
-	for (i = 0; i < nparents; i++) {
+	for (i = 0; i < nparents; i++)
 		add_line_range(rev, parents[i], cand[i]);
-	}
 
+	ret = 1;
+
+out:
 	clear_commit_line_range(rev, commit);
 	free(parents);
+	for (i = 0; i < nparents; i++) {
+		if (!cand[i])
+			continue;
+		line_log_data_clear(cand[i]);
+		free(cand[i]);
+	}
 	free(cand);
 	free_diffqueues(nparents, diffqueues);
-	return 1;
+	return ret;
 
 	/* NEEDSWORK evil merge detection stuff */
-	/* NEEDSWORK leaking like a sieve */
 }
 
 int line_log_process_ranges_arbitrary_commit(struct rev_info *rev, struct commit *commit)