From 6af46f9aa5a2966e5aa93d69d53893b8976918ca Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marc=20Andr=C3=A9=20Tanner?= <mat@brain-dump.org>
Date: Thu, 1 Jun 2017 22:31:23 +0200
Subject: vis-lua: avoid string memory leaks in error case

The function lua_pushstring can throw an error, meaning it
will setjmp(3) out thereby leaking the allocated memory.
By using lua_newuserdata we let Lua free the memory during
a GC run.
---
 vis-lua.c | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/vis-lua.c b/vis-lua.c
index 8a0f0dc..2a7479d 100644
--- a/vis-lua.c
+++ b/vis-lua.c
@@ -2157,12 +2157,11 @@ static int file_lines_iterator_it(lua_State *L) {
 		return 0;
 	size_t end = text_line_end(file->text, *start);
 	size_t len = end - *start;
-	char *buf = malloc(len);
+	char *buf = lua_newuserdata(L, len);
 	if (!buf && len)
 		return 0;
 	len = text_bytes_get(file->text, *start, len, buf);
 	lua_pushlstring(L, buf, len);
-	free(buf);
 	*start = text_line_next(file->text, end);
 	return 1;
 }
@@ -2192,12 +2191,11 @@ static int file_content(lua_State *L) {
 	if (!text_range_valid(&range))
 		goto err;
 	size_t len = text_range_size(&range);
-	char *data = malloc(len);
+	char *data = lua_newuserdata(L, len);
 	if (!data)
 		goto err;
 	len = text_bytes_get(file->text, range.start, len, data);
 	lua_pushlstring(L, data, len);
-	free(data);
 	return 1;
 err:
 	lua_pushnil(L);
@@ -2287,12 +2285,11 @@ static int file_lines_index(lua_State *L) {
 	size_t end = text_line_end(txt, start);
 	if (start != EPOS && end != EPOS) {
 		size_t size = end - start;
-		char *data = malloc(size);
+		char *data = lua_newuserdata(L, size);
 		if (!data && size)
 			goto err;
 		size = text_bytes_get(txt, start, size, data);
 		lua_pushlstring(L, data, size);
-		free(data);
 		return 1;
 	}
 err:
-- 
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