avoid memory errors while a file is locked (when reading a line)

This commit is contained in:
Roberto Ierusalimschy 2014-11-21 10:17:33 -02:00
parent 5fbd40dbe5
commit 1735c05ac7

View File

@ -1,5 +1,5 @@
/*
** $Id: liolib.c,v 2.139 2014/11/02 19:19:04 roberto Exp roberto $
** $Id: liolib.c,v 2.140 2014/11/02 19:33:33 roberto Exp roberto $
** Standard I/O (and system) library
** See Copyright Notice in lua.h
*/
@ -466,12 +466,21 @@ static int read_line (lua_State *L, FILE *f, int chop) {
luaL_Buffer b;
int c;
luaL_buffinit(L, &b);
l_lockfile(f);
while ((c = l_getc(f)) != EOF && c != '\n')
luaL_addchar(&b, c);
for (;;) {
char *buff = luaL_prepbuffer(&b); /* pre-allocate buffer */
int i = 0;
l_lockfile(f); /* no memory errors can happen inside the lock */
while (i < LUAL_BUFFERSIZE && (c = l_getc(f)) != EOF && c != '\n')
buff[i++] = c;
l_unlockfile(f);
if (!chop && c == '\n') luaL_addchar(&b, c);
luaL_addsize(&b, i);
if (i < LUAL_BUFFERSIZE)
break;
}
if (!chop && c == '\n') /* want a newline and have one? */
luaL_addchar(&b, c); /* add ending newline to result */
luaL_pushresult(&b); /* close buffer */
/* return ok if read something (either a newline or something else) */
return (c == '\n' || lua_rawlen(L, -1) > 0);
}
@ -516,7 +525,7 @@ static int g_read (lua_State *L, FILE *f, int first) {
success = 1;
for (n = first; nargs-- && success; n++) {
if (lua_type(L, n) == LUA_TNUMBER) {
size_t l = (size_t)lua_tointeger(L, n);
size_t l = (size_t)luaL_checkinteger(L, n);
success = (l == 0) ? test_eof(L, f) : read_chars(L, f, l);
}
else {