Bug: wrong initialization in result from 'gmatch'

Function returned by 'string.gmatch' can be left in an inconsistent
state after an error.

1 files changed, 8 insertions, 2 deletions

diff --git a/lstrlib.c b/lstrlib.c
index 874cec80..dd3c0fd0 100644
--- a/lstrlib.c
+++ b/lstrlib.c
@@ -757,19 +757,25 @@ static int nospecials (const char *p, size_t l) {
 }
 
 
+/*
+** Prepare state for matches. These fields are not affected by each match.
+*/
 static void prepstate (MatchState *ms, lua_State *L,
                        const char *s, size_t ls, const char *p, size_t lp) {
   ms->L = L;
-  ms->matchdepth = MAXCCALLS;
   ms->src_init = s;
   ms->src_end = s + ls;
   ms->p_end = p + lp;
 }
 
 
+/*
+** (Re)prepare state for a match, setting fields that change during
+** each match.
+*/
 static void reprepstate (MatchState *ms) {
+  ms->matchdepth = MAXCCALLS;
   ms->level = 0;
-  lua_assert(ms->matchdepth == MAXCCALLS);
 }