Index: driver/utility.c
===================================================================
--- driver/utility.c	(revision 977)
+++ driver/utility.c	(working copy)
@@ -132,15 +132,12 @@
       irrec->precision= (SQLSMALLINT) irrec->length;
       break;
     }
-    irrec->octet_length= get_transfer_octet_length(stmt, field) +
-                         test(field->charsetnr != BINARY_CHARSET_NUMBER);
-    if (stmt->dbc->flag & FLAG_COLUMN_SIZE_S32)
-    {
-      if (irrec->length > INT_MAX32)
-        irrec->length= INT_MAX32;
-      if (irrec->octet_length > INT_MAX32)
-        irrec->octet_length= INT_MAX32;
-    }
+    irrec->octet_length= get_transfer_octet_length(stmt, field);
+    /* prevent overflowing */
+    if (irrec->octet_length < INT_MAX32)
+      irrec->octet_length+= test(field->charsetnr != BINARY_CHARSET_NUMBER);
+    if (stmt->dbc->flag & FLAG_COLUMN_SIZE_S32 && irrec->length > INT_MAX32)
+      irrec->length= INT_MAX32;
     irrec->scale= max(0, (SQLSMALLINT) get_decimal_digits(stmt, field));
     if ((field->flags & NOT_NULL_FLAG) &&
         !(field->flags & TIMESTAMP_FLAG) &&
@@ -1261,7 +1258,12 @@
 */
 SQLLEN get_transfer_octet_length(STMT *stmt, MYSQL_FIELD *field)
 {
-  SQLLEN length= field->length;
+  SQLLEN length;
+  /* cap at INT_MAX32 due to signed value */
+  if (field->length > INT_MAX32)
+    length= INT_MAX32;
+  else
+    length= field->length;
 
   switch (field->type) {
   case MYSQL_TYPE_TINY:
@@ -1418,10 +1420,17 @@
   case MYSQL_TYPE_LONG_BLOB:
   case MYSQL_TYPE_BLOB:
   case MYSQL_TYPE_GEOMETRY:
-    if (field->charsetnr == BINARY_CHARSET_NUMBER)
-      return field->length * 2;
-    else
-      return field->length / mbmaxlen;
+    {
+      unsigned long length;
+      if (field->charsetnr == BINARY_CHARSET_NUMBER)
+        length= field->length * 2;
+      else
+        length= field->length / mbmaxlen;
+      /* display size is signed and cannot exceed this */
+      if (length > INT_MAX32)
+        length= INT_MAX32;
+      return length;
+    }
   }
 
   return SQL_NO_TOTAL;
Index: test/my_result.c
===================================================================
--- test/my_result.c	(revision 977)
+++ test/my_result.c	(working copy)
@@ -2025,6 +2025,7 @@
   SQLULEN     pcColSz;
   SQLCHAR     szColName[MAX_NAME_LEN];
   SQLSMALLINT pfSqlType, pcbScale, pfNullable;
+  SQLLEN display_size, octet_length;
 
   SET_DSN_OPTION(1 << 27);
 
@@ -2041,6 +2042,14 @@
   /* Size of LONGTEXT should have been capped to 1 << 31. */
   is_num(pcColSz, 2147483647L);
 
+  /* also, check display size and octet length (see bug#30890) */
+  ok_stmt(hstmt1, SQLColAttribute(hstmt1, 1, SQL_DESC_DISPLAY_SIZE, NULL,
+                                  0, NULL, &display_size));
+  ok_stmt(hstmt1, SQLColAttribute(hstmt1, 1, SQL_DESC_OCTET_LENGTH, NULL,
+                                  0, NULL, &octet_length));
+  is_num(display_size, 2147483647L);
+  is_num(octet_length, 2147483647L);
+
   ok_stmt(hstmt1, SQLFreeStmt(hstmt1, SQL_CLOSE));
 
   ok_sql(hstmt1, "DROP TABLE IF EXISTS t_bug13776");