Merge zippy.cornsilk.net:/home/cmiller/work/mysql/bug15776/my50-bug15776

into  zippy.cornsilk.net:/home/cmiller/work/mysql/bug15776/my51-bug15776

1 files changed, 17 insertions, 7 deletions

diff --git a/sql/field.cc b/sql/field.cc
index a7a76d6c950..2b6d5235003 100644
--- a/sql/field.cc
+++ b/sql/field.cc
@@ -7082,6 +7082,7 @@ uint32 Field_blob::get_length(const uchar *pos)
       return (uint32) tmp;
     }
   }
+  /* When expanding this, see also MAX_FIELD_BLOBLENGTH. */
   return 0;					// Impossible
 }
 
@@ -8772,11 +8773,11 @@ bool Create_field::init(THD *thd, char *fld_name, enum_field_types fld_type,
       (fld_type_modifier & NOT_NULL_FLAG) && fld_type != MYSQL_TYPE_TIMESTAMP)
     flags|= NO_DEFAULT_VALUE_FLAG;
 
-  if (fld_length != 0)
+  if (fld_length != NULL)
   {
     errno= 0;
     length= strtoul(fld_length, NULL, 10);
-    if (errno != 0)
+    if ((errno != 0) || (length > MAX_FIELD_BLOBLENGTH))
     {
       my_error(ER_TOO_BIG_DISPLAYWIDTH, MYF(0), fld_name, MAX_FIELD_BLOBLENGTH);
       DBUG_RETURN(TRUE);
@@ -8933,7 +8934,7 @@ bool Create_field::init(THD *thd, char *fld_name, enum_field_types fld_type,
     }
     break;
   case MYSQL_TYPE_TIMESTAMP:
-    if (!fld_length)
+    if (fld_length == NULL)
     {
       /* Compressed date YYYYMMDDHHMMSS */
       length= MAX_DATETIME_COMPRESSED_WIDTH;
@@ -8942,12 +8943,21 @@ bool Create_field::init(THD *thd, char *fld_name, enum_field_types fld_type,
     {
       /*
         We support only even TIMESTAMP lengths less or equal than 14
-        and 19 as length of 4.1 compatible representation.
+        and 19 as length of 4.1 compatible representation.  Silently 
+        shrink it to MAX_DATETIME_COMPRESSED_WIDTH.
       */
-      length= ((length+1)/2)*2; /* purecov: inspected */
-      length= min(length, MAX_DATETIME_COMPRESSED_WIDTH); /* purecov: inspected */
+	  DBUG_ASSERT(MAX_DATETIME_COMPRESSED_WIDTH < UINT_MAX);
+      if (length != UINT_MAX)  /* avoid overflow; is safe because of min() */
+        length= ((length+1)/2)*2;
+      length= min(length, MAX_DATETIME_COMPRESSED_WIDTH);
     }
     flags|= ZEROFILL_FLAG | UNSIGNED_FLAG;
+    /*
+      Since we silently rewrite down to MAX_DATETIME_COMPRESSED_WIDTH bytes,
+      the parser should not raise errors unless bizzarely large. 
+     */
+    max_field_charlength= UINT_MAX;
+
     if (fld_default_value)
     {
       /* Grammar allows only NOW() value for ON UPDATE clause */
@@ -9054,7 +9064,7 @@ bool Create_field::init(THD *thd, char *fld_name, enum_field_types fld_type,
       ((length > max_field_charlength && fld_type != MYSQL_TYPE_SET &&
         fld_type != MYSQL_TYPE_ENUM &&
         (fld_type != MYSQL_TYPE_VARCHAR || fld_default_value)) ||
-       (!length &&
+       ((length == 0) &&
         fld_type != MYSQL_TYPE_STRING &&
         fld_type != MYSQL_TYPE_VARCHAR && fld_type != MYSQL_TYPE_GEOMETRY)))
   {