1 files changed, 23 insertions, 15 deletions

diff --git a/lpvm.c b/lpvm.c
index c256083..911b4c5 100644
--- a/lpvm.c
+++ b/lpvm.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lpvm.c,v 1.6 2015/09/28 17:01:25 roberto Exp $
+** $Id: lpvm.c,v 1.9 2016/06/03 20:11:18 roberto Exp $
 ** Copyright 2007, Lua.org & PUC-Rio  (see 'lpeg.html' for license)
 */
 
@@ -33,6 +33,7 @@ static void setlabelfail(Labelset *ls) {
 }
 /* labeled failure end */
 
+
 /*
 ** {======================================================
 ** Virtual Machine
@@ -52,14 +53,16 @@ typedef struct Stack {
 
 
 /*
-** Double the size of the array of captures
+** Make the size of the array of captures 'cap' twice as large as needed
+** (which is 'captop'). ('n' is the number of new elements.)
 */
-static Capture *doublecap (lua_State *L, Capture *cap, int captop, int ptop) {
+static Capture *doublecap (lua_State *L, Capture *cap, int captop,
+                                         int n, int ptop) {
   Capture *newc;
   if (captop >= INT_MAX/((int)sizeof(Capture) * 2))
     luaL_error(L, "too many captures");
   newc = (Capture *)lua_newuserdata(L, captop * 2 * sizeof(Capture));
-  memcpy(newc, cap, captop * sizeof(Capture));
+  memcpy(newc, cap, (captop - n) * sizeof(Capture));
   lua_replace(L, caplistidx(ptop));
   return newc;
 }
@@ -120,8 +123,8 @@ static int resdyncaptures (lua_State *L, int fr, int curr, int limit) {
 */
 static void adddyncaptures (const char *s, Capture *base, int n, int fd) {
   int i;
-  /* Cgroup capture is already there */
-  assert(base[0].kind == Cgroup && base[0].siz == 0);
+  base[0].kind = Cgroup;  /* create group capture */
+  base[0].siz = 0;
   base[0].idx = 0;  /* make it an anonymous group */
   for (i = 1; i <= n; i++) {  /* add runtime captures */
     base[i].kind = Cruntime;
@@ -148,8 +151,6 @@ static int removedyncap (lua_State *L, Capture *capture,
 }
 
 
-
-
 /*
 ** Opcode interpreter
 */
@@ -170,10 +171,11 @@ const char *match (lua_State *L, const char *o, const char *s, const char *e,
   lua_pushlightuserdata(L, stackbase);
   for (;;) {
 #if defined(DEBUG)
-        printinst(op, p);
-      printf("s: |%s| stck:%d, dyncaps:%d, caps:%d  ",
-             s, stack - getstackbase(L, ptop), ndyncap, captop);
+      printf("-------------------------------------\n");
       printcaplist(capture, capture + captop);
+      printf("s: |%s| stck:%d, dyncaps:%d, caps:%d  ",
+             s, (int)(stack - getstackbase(L, ptop)), ndyncap, captop);
+      printinst(op, p);
 #endif
     assert(stackidx(ptop) + ndyncap == lua_gettop(L) && ndyncap <= captop);
     switch ((Opcode)p->i.code) {
@@ -275,7 +277,7 @@ const char *match (lua_State *L, const char *o, const char *s, const char *e,
         p += 2;
         continue;
       }
-                        case IRecov: { /* labeled failure */
+      case IRecov: { /* labeled failure */
         if (stack == stacklimit)
           stack = doublestack(L, &stacklimit, ptop);
         stack->p = p + getoffset(p);
@@ -354,6 +356,9 @@ const char *match (lua_State *L, const char *o, const char *s, const char *e,
                                         stack++;
                                 }
         p = pstack->p;
+#if defined(DEBUG)
+        printf("**FAIL**\n");
+#endif
         continue;
       }
       case ICloseRunTime: {
@@ -363,6 +368,7 @@ const char *match (lua_State *L, const char *o, const char *s, const char *e,
         cs.s = o; cs.L = L; cs.ocap = capture; cs.ptop = ptop;
         n = runtimecap(&cs, capture + captop, s, &rem);  /* call function */
         captop -= n;  /* remove nested captures */
+        ndyncap -= rem;  /* update number of dynamic captures */
         fr -= rem;  /* 'rem' items were popped from Lua stack */
         res = resdyncaptures(L, fr, s - o, e - o);  /* get result */
         if (res == -1) { /* fail? */
@@ -373,10 +379,12 @@ const char *match (lua_State *L, const char *o, const char *s, const char *e,
         }
         s = o + res;  /* else update current position */
         n = lua_gettop(L) - fr + 1;  /* number of new captures */
-        ndyncap += n - rem;  /* update number of dynamic captures */
+        ndyncap += n;  /* update number of dynamic captures */
         if (n > 0) {  /* any new capture? */
+          if (fr + n >= SHRT_MAX)
+            luaL_error(L, "too many results in match-time capture");
           if ((captop += n + 2) >= capsize) {
-            capture = doublecap(L, capture, captop, ptop);
+            capture = doublecap(L, capture, captop, n + 2, ptop);
             capsize = 2 * captop;
           }
           /* add new captures to 'capture' list */
@@ -413,7 +421,7 @@ const char *match (lua_State *L, const char *o, const char *s, const char *e,
         capture[captop].idx = p->i.key;
         capture[captop].kind = getkind(p);
         if (++captop >= capsize) {
-          capture = doublecap(L, capture, captop, ptop);
+          capture = doublecap(L, capture, captop, 0, ptop);
           capsize = 2 * captop;
         }
         p++;