[Midnightbsd-cvs] src: skeleton.c: Fix a security issue with yacc.

[laffer1 at midnightbsd.org]

Log Message:
-----------
Fix a security issue with yacc.  

Obtained from DragonFly.

Modified Files:
--------------
    src/usr.bin/yacc:
        skeleton.c (r1.1.1.1 -> r1.2)

-------------- next part --------------
Index: skeleton.c
===================================================================
RCS file: /home/cvs/src/usr.bin/yacc/skeleton.c,v
retrieving revision 1.1.1.1
retrieving revision 1.2
diff -L usr.bin/yacc/skeleton.c -L usr.bin/yacc/skeleton.c -u -r1.1.1.1 -r1.2
--- usr.bin/yacc/skeleton.c
+++ usr.bin/yacc/skeleton.c
@@ -60,6 +60,7 @@
 const char *banner[] =
 {
     "#include <stdlib.h>",
+    "#include <string.h>",
     "#ifndef lint",
     "#ifdef __unused",
     "__unused",
@@ -331,6 +332,10 @@
     "                YYPREFIX, yystate, yyn, yyrule[yyn]);",
     "#endif",
     "    yym = yylen[yyn];",
+    "    if (yym)",
+    "        yyval = yyvsp[1-yym];",
+    "    else",
+    "        memset(&yyval, 0, sizeof yyval);",
     "    yyval = yyvsp[1-yym];",
     "    switch (yyn)",
     "    {",