Follow-up to B-g#15776, test failures on 64-bit linux.

Make maximum blob size to be 2**32-1, regardless of word size.

Fix failure of timestamp with size of 2**31-1.  The method of
rounding up to the nearest even number would overflow.


mysql-test/r/type_blob.result:
  2**32-1 is not a special case for timestamp.
  
  Test 2**32-1 and 2**64 as the reliable test points for both 32-
  and 64-bit machines.  I'd like to test 2**32, but that would make 
  tests that vary between architectures.
  
  I'd like to generalize the tests by pulling the max blob size from
  the server, and then "eval"ing N-1, N, and N+1 instead of all these
  literal numbers, but I have not found a way to get UINT_MAX.
mysql-test/t/type_blob.test:
  2**32-1 is not a special case for timestamp.
  
  Test 2**32-1 and 2**64 as the reliable test points for both 32-
  and 64-bit machines.  I'd like to test 2**32, but that would make 
  tests that vary between architectures.
  
  I'd like to generalize the tests by pulling the max blob size from
  the server, and then "eval"ing N-1, N, and N+1 instead of all these
  literal numbers, but I have not found a way to get UINT_MAX.
sql/field.cc:
  Fix a bug where the round-to-even code for TIMESTAMP fields
  failed where the size would overflow the size to zero and then
  fail.
  
  Also, since we silently truncate the size of TIMESTAMP fields, set
  the maximum size we report is allowable to be the largest parsable
  number.
sql/unireg.h:
  Make BLOB size the maximum that the packed value in 
  field_blob::get_length() allows.

2 files changed, 18 insertions, 8 deletions

diff --git a/sql/field.cc b/sql/field.cc
index 2950f349580..99b61ec1ee0 100644
--- a/sql/field.cc
+++ b/sql/field.cc
@@ -6848,6 +6848,7 @@ uint32 Field_blob::get_length(const char *pos)
       return (uint32) tmp;
     }
   }
+  /* When expanding this, see also MAX_FIELD_BLOBLENGTH. */
   return 0;					// Impossible
 }
 
@@ -8395,11 +8396,11 @@ bool create_field::init(THD *thd, char *fld_name, enum_field_types fld_type,
       (fld_type_modifier & NOT_NULL_FLAG) && fld_type != FIELD_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);
@@ -8556,7 +8557,7 @@ bool create_field::init(THD *thd, char *fld_name, enum_field_types fld_type,
     }
     break;
   case FIELD_TYPE_TIMESTAMP:
-    if (!fld_length)
+    if (fld_length == NULL)
     {
       /* Compressed date YYYYMMDDHHMMSS */
       length= MAX_DATETIME_COMPRESSED_WIDTH;
@@ -8565,12 +8566,21 @@ 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 */
@@ -8677,7 +8687,7 @@ bool create_field::init(THD *thd, char *fld_name, enum_field_types fld_type,
       ((length > max_field_charlength && fld_type != FIELD_TYPE_SET &&
         fld_type != FIELD_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 != FIELD_TYPE_GEOMETRY)))
   {
diff --git a/sql/unireg.h b/sql/unireg.h
index 0ab2a40048b..24e57b4e584 100644
--- a/sql/unireg.h
+++ b/sql/unireg.h
@@ -60,7 +60,7 @@
 #define MAX_MBWIDTH		3		/* Max multibyte sequence */
 #define MAX_FIELD_CHARLENGTH	255
 #define MAX_FIELD_VARCHARLENGTH	65535
-#define MAX_FIELD_BLOBLENGTH    UINT_MAX
+#define MAX_FIELD_BLOBLENGTH UINT_MAX32     /* cf field_blob::get_length() */
 #define CONVERT_IF_BIGGER_TO_BLOB 512		/* Used for CREATE ... SELECT */
 
 /* Max column width +1 */