Fix for lp:909635: MariaDB crashes on a select with long varchar and blob fields

Problem was a crash in internal temporary (Maria) files when row length exceeded 65535

mysql-test/suite/maria/r/maria3.result:
  Added test case
mysql-test/suite/maria/t/maria3.test:
  Added test case
storage/maria/ma_open.c:
  Added support for row length > 65535.
  This fixes crash when using tables with longer row lengths.

mysql-test/suite/maria/r/maria3.result

@@ -617,3 +617,27 @@ ERROR 23000: Duplicate entry '2' for key 'a'
 insert into t1 values(3);
 insert into t2 values(3);
 drop table t1, t2;
+CREATE TABLE t1 (
+a INT PRIMARY KEY,
+b CHAR(255),
+c VARCHAR(2048),
+d VARCHAR(18990),
+e CHAR(128),
+f CHAR(192)
+) ENGINE=MyISAM DEFAULT CHARSET=utf8;
+INSERT INTO t1 VALUES
+(1,'A','B','C','','D'),
+(2,'Abcdefghi','E','F','','G');
+CREATE TABLE t2 (
+g INT PRIMARY KEY,
+h CHAR(32),
+i CHAR(255),
+j TEXT
+) ENGINE=MyISAM DEFAULT CHARSET=utf8;
+INSERT INTO t2 VALUES (1,'M','','H'),
+(2,'N','','H');
+SELECT * FROM t1, t2 WHERE a = g ORDER BY b;
+a	b	c	d	e	f	g	h	i	j
+1	A	B	C		D	1	M		H
+2	Abcdefghi	E	F		G	2	N		H
+drop table t1,t2;

mysql-test/suite/maria/t/maria3.test

@@ -524,6 +524,37 @@ insert into t2 values(3);
 connection default;
 drop table t1, t2;
 
+#
+# BUG#909635 - MariaDB crashes on a select with long varchar and blob fields
+#
+
+CREATE TABLE t1 (
+  a INT PRIMARY KEY,
+  b CHAR(255),
+  c VARCHAR(2048),
+  d VARCHAR(18990),
+  e CHAR(128),
+  f CHAR(192)
+) ENGINE=MyISAM DEFAULT CHARSET=utf8;
+
+INSERT INTO t1 VALUES
+  (1,'A','B','C','','D'),
+  (2,'Abcdefghi','E','F','','G');
+
+CREATE TABLE t2 (
+  g INT PRIMARY KEY,
+  h CHAR(32),
+  i CHAR(255),
+  j TEXT
+) ENGINE=MyISAM DEFAULT CHARSET=utf8;
+
+INSERT INTO t2 VALUES (1,'M','','H'),
+  (2,'N','','H');
+
+SELECT * FROM t1, t2 WHERE a = g ORDER BY b;
+drop table t1,t2;
+
+
 # End of 5.1 tests
 
 --disable_result_log

storage/maria/ma_open.c

@@ -1669,9 +1669,11 @@ my_bool _ma_columndef_write(File file, MARIA_COLUMNDEF *columndef)
 {
   uchar buff[MARIA_COLUMNDEF_SIZE];
   uchar *ptr=buff;
+  uint low_offset=  (uint) (columndef->offset & 0xffff);
+  uint high_offset= (uint) (columndef->offset >> 16);
 
   mi_int2store(ptr,(ulong) columndef->column_nr); ptr+= 2;
-  mi_int2store(ptr,(ulong) columndef->offset);	  ptr+= 2;
+  mi_int2store(ptr, low_offset);		  ptr+= 2;
   mi_int2store(ptr,columndef->type);		  ptr+= 2;
   mi_int2store(ptr,columndef->length);		  ptr+= 2;
   mi_int2store(ptr,columndef->fill_length);	  ptr+= 2;
@@ -1680,12 +1682,14 @@ my_bool _ma_columndef_write(File file, MARIA_COLUMNDEF *columndef)
 
   (*ptr++)= columndef->null_bit;
   (*ptr++)= columndef->empty_bit;
-  ptr[0]= ptr[1]= ptr[2]= ptr[3]= 0;            ptr+= 4;  /* For future */
+  mi_int2store(ptr, high_offset);                 ptr+= 2;
+  ptr[0]= ptr[1]= 0;                              ptr+= 2;  /* For future */
   return my_write(file, buff, (size_t) (ptr-buff), MYF(MY_NABP)) != 0;
 }
 
 uchar *_ma_columndef_read(uchar *ptr, MARIA_COLUMNDEF *columndef)
 {
+  uint high_offset;
   columndef->column_nr= mi_uint2korr(ptr);      ptr+= 2;
   columndef->offset= mi_uint2korr(ptr);         ptr+= 2;
   columndef->type=   mi_sint2korr(ptr);		ptr+= 2;
@@ -1695,7 +1699,9 @@ uchar *_ma_columndef_read(uchar *ptr, MARIA_COLUMNDEF *columndef)
   columndef->empty_pos= mi_uint2korr(ptr);	ptr+= 2;
   columndef->null_bit=  (uint8) *ptr++;
   columndef->empty_bit= (uint8) *ptr++;
-  ptr+= 4;
+  high_offset=       mi_uint2korr(ptr);         ptr+= 2;  
+  columndef->offset|= ((ulong) high_offset << 16);
+  ptr+= 2;
   return ptr;
 }