merge 5.1 => 5.5

include/decimal.h

@@ -21,6 +21,15 @@ typedef enum
   decimal_round_mode;
 typedef int32 decimal_digit_t;
 
+/**
+    intg is the number of *decimal* digits (NOT number of decimal_digit_t's !)
+         before the point
+    frac is the number of decimal digits after the point
+    len  is the length of buf (length of allocated space) in decimal_digit_t's,
+         not in bytes
+    sign false means positive, true means negative
+    buf  is an array of decimal_digit_t's
+ */
 typedef struct st_decimal_t {
   int    intg, frac, len;
   my_bool sign;

mysql-test/r/type_newdecimal.result

@@ -1934,3 +1934,14 @@ f1
 0.000000000000000000000000
 DROP TABLE IF EXISTS t1;
 End of 5.1 tests
+#
+# BUG#12911710 - VALGRIND FAILURE IN 
+# ROW-DEBUG:PERFSCHEMA.SOCKET_SUMMARY_BY_INSTANCE_FUNC 
+#
+CREATE TABLE t1(d1 DECIMAL(60,0) NOT NULL,
+d2 DECIMAL(60,0) NOT NULL);
+INSERT INTO t1 (d1, d2) VALUES(0.0, 0.0);
+SELECT d1 * d2 FROM t1;
+d1 * d2
+0
+DROP TABLE t1;

mysql-test/t/type_newdecimal.test

@@ -1535,3 +1535,17 @@ DROP TABLE IF EXISTS t1;
 
 
 --echo End of 5.1 tests
+
+--echo #
+--echo # BUG#12911710 - VALGRIND FAILURE IN 
+--echo # ROW-DEBUG:PERFSCHEMA.SOCKET_SUMMARY_BY_INSTANCE_FUNC 
+--echo #
+
+CREATE TABLE t1(d1 DECIMAL(60,0) NOT NULL,
+                d2 DECIMAL(60,0) NOT NULL);
+
+INSERT INTO t1 (d1, d2) VALUES(0.0, 0.0);
+SELECT d1 * d2 FROM t1;
+
+DROP TABLE t1;
+

sql/my_decimal.h

@@ -124,12 +124,8 @@ public:
   {
     len= DECIMAL_BUFF_LENGTH;
     buf= buffer;
-#if !defined (HAVE_purify) && !defined(DBUG_OFF)
-    /* Set buffer to 'random' value to find wrong buffer usage */
-    for (uint i= 0; i < DECIMAL_BUFF_LENGTH; i++)
-      buffer[i]= i;
-#endif
   }
+
   my_decimal()
   {
     init();

strings/decimal.c

@@ -1403,11 +1403,18 @@ int bin2decimal(const uchar *from, decimal_t *to, int precision, int scale)
     buf++;
   }
   my_afree(d_copy);
+
+  /*
+    No digits? We have read the number zero, of unspecified precision.
+    Make it a proper zero, with non-zero precision.
+  */
+  if (to->intg == 0 && to->frac == 0)
+    decimal_make_zero(to);
   return error;
 
 err:
   my_afree(d_copy);
-  decimal_make_zero(((decimal_t*) to));
+  decimal_make_zero(to);
   return(E_DEC_BAD_NUM);
 }