Bug: tbc variables in "for" loops don't avoid tail calls

1 files changed, 15 insertions, 6 deletions

diff --git a/lparser.c b/lparser.c
index 284ef1f0..df9473c2 100644
--- a/lparser.c
+++ b/lparser.c
@@ -417,6 +417,17 @@ static void markupval (FuncState *fs, int level) {
 
 
 /*
+** Mark that current block has a to-be-closed variable.
+*/
+static void marktobeclosed (FuncState *fs) {
+  BlockCnt *bl = fs->bl;
+  bl->upval = 1;
+  bl->insidetbc = 1;
+  fs->needclose = 1;
+}
+
+
+/*
 ** Find a variable with the given name 'n'. If it is an upvalue, add
 ** this upvalue into all intermediate functions. If it is a global, set
 ** 'var' as 'void' as a flag.
@@ -1599,7 +1610,7 @@ static void forlist (LexState *ls, TString *indexname) {
   line = ls->linenumber;
   adjust_assign(ls, 4, explist(ls, &e), &e);
   adjustlocalvars(ls, 4);  /* control variables */
-  markupval(fs, fs->nactvar);  /* last control var. must be closed */
+  marktobeclosed(fs);  /* last control var. must be closed */
   luaK_checkstack(fs, 3);  /* extra space to call generator */
   forbody(ls, base, line, nvars - 4, 1);
 }
@@ -1703,11 +1714,9 @@ static int getlocalattribute (LexState *ls) {
 }
 
 
-static void checktoclose (LexState *ls, int level) {
+static void checktoclose (FuncState *fs, int level) {
   if (level != -1) {  /* is there a to-be-closed variable? */
-    FuncState *fs = ls->fs;
-    markupval(fs, level + 1);
-    fs->bl->insidetbc = 1;  /* in the scope of a to-be-closed variable */
+    marktobeclosed(fs);
     luaK_codeABC(fs, OP_TBC, reglevel(fs, level), 0, 0);
   }
 }
@@ -1751,7 +1760,7 @@ static void localstat (LexState *ls) {
     adjust_assign(ls, nvars, nexps, &e);
     adjustlocalvars(ls, nvars);
   }
-  checktoclose(ls, toclose);
+  checktoclose(fs, toclose);
 }