Merge from mysql-5.1 for bug#58026.

3 files changed, 21 insertions, 4 deletions

diff --git a/regex/my_regex.h b/regex/my_regex.h
index 0d1cedf5430..30896e29b91 100644
--- a/regex/my_regex.h
+++ b/regex/my_regex.h
@@ -28,6 +28,7 @@ typedef struct {
 
 
 /* === regcomp.c === */
+typedef int (*my_regex_stack_check_t)();
 extern int my_regcomp(my_regex_t *, const char *, int, CHARSET_INFO *charset);
 #define	REG_BASIC	0000
 #define	REG_EXTENDED	0001
@@ -76,7 +77,8 @@ extern void my_regfree(my_regex_t *);
 
 /* === reginit.c === */
 
-extern void my_regex_init(CHARSET_INFO *cs);	/* Should be called for multithread progs */
+/* Should be called for multithread progs */
+extern void my_regex_init(CHARSET_INFO *cs,  my_regex_stack_check_t func);
 extern void my_regex_end(void);	/* If one wants a clean end */
 
 #ifdef __cplusplus
diff --git a/regex/regcomp.c b/regex/regcomp.c
index b41a1ae6da9..6e2d2511fc1 100644
--- a/regex/regcomp.c
+++ b/regex/regcomp.c
@@ -31,6 +31,9 @@ struct parse {
 	CHARSET_INFO *charset;	/* for ctype things  */
 };
 
+/* Check if there is enough stack space for recursion. */
+my_regex_stack_check_t my_regex_enough_mem_in_stack= NULL;
+
 #include "regcomp.ih"
 
 static char nuls[10];		/* place to point scanner in event of error */
@@ -117,7 +120,7 @@ CHARSET_INFO *charset;
 #	define	GOODFLAGS(f)	((f)&~REG_DUMP)
 #endif
 
-	my_regex_init(charset);	/* Init cclass if neaded */
+	my_regex_init(charset, NULL);	/* Init cclass if neaded */
 	preg->charset=charset;
 	cflags = GOODFLAGS(cflags);
 	if ((cflags&REG_EXTENDED) && (cflags&REG_NOSPEC))
@@ -222,7 +225,15 @@ int stop;			/* character this ERE should end at */
 		/* do a bunch of concatenated expressions */
 		conc = HERE();
 		while (MORE() && (c = PEEK()) != '|' && c != stop)
-			p_ere_exp(p);
+		{
+		  if (my_regex_enough_mem_in_stack &&
+		      my_regex_enough_mem_in_stack())
+		  {
+		    SETERROR(REG_ESPACE);
+		    return;
+		  }
+		  p_ere_exp(p);
+		}
 		if(REQUIRE(HERE() != conc, REG_EMPTY)) {}/* require nonempty */
 
 		if (!EAT('|'))
diff --git a/regex/reginit.c b/regex/reginit.c
index 5980de24030..3d2cd64d1e7 100644
--- a/regex/reginit.c
+++ b/regex/reginit.c
@@ -4,10 +4,12 @@
 #include <m_ctype.h>
 #include <m_string.h>
 #include "cclass.h"
+#include "my_regex.h"
 
 static my_bool regex_inited=0;
+extern my_regex_stack_check_t my_regex_enough_mem_in_stack;
 
-void my_regex_init(CHARSET_INFO *cs)
+void my_regex_init(CHARSET_INFO *cs, my_regex_stack_check_t func)
 {
   char buff[CCLASS_LAST][256];
   int  count[CCLASS_LAST];
@@ -16,6 +18,7 @@ void my_regex_init(CHARSET_INFO *cs)
   if (!regex_inited)
   {
     regex_inited=1;
+    my_regex_enough_mem_in_stack= func;
     bzero((uchar*) &count,sizeof(count));
 
     for (i=1 ; i<= 255; i++)
@@ -74,6 +77,7 @@ void my_regex_end()
     int i;
     for (i=0; i < CCLASS_LAST ; i++)
       free((char*) cclasses[i].chars);
+    my_regex_enough_mem_in_stack= NULL;
     regex_inited=0;
   }
 }