Merge

mysql-test/r/bdb.result

@@ -1190,6 +1190,22 @@ a
 A
 a
 drop table t1;
+create table t1(
+pk1 text not null, pk2 text not null, pk3 char(4),
+key1 int, key2 int,
+primary key(pk1(4), pk2(4), pk3), key(key1), key(key2)
+) engine=bdb;
+insert into t1 values (concat('aaa-', repeat('A', 4000)),
+concat('eee-', repeat('e', 4000)), 'a++a', 1, 1);
+insert into t1 values (concat('bbb-', repeat('B', 4000)),
+concat('ggg-', repeat('G', 4000)), 'b++b', 1, 1);
+select substring(pk1, 1, 4), substring(pk1, 4001),
+substring(pk2, 1, 4), substring(pk2, 4001), pk3, key1, key2
+from t1 force index(key1, key2) where key1 < 3 or key2 < 3;
+substring(pk1, 1, 4)	substring(pk1, 4001)	substring(pk2, 1, 4)	substring(pk2, 4001)	pk3	key1	key2
+aaa-	AAAA	eee-	eeee	a++a	1	1
+bbb-	BBBB	ggg-	GGGG	b++b	1	1
+drop table t1;
 create table t1 (
 pk1 varchar(8) not null default '',
 pk2 varchar(4) not null default '',

mysql-test/t/bdb.test

@@ -830,6 +830,25 @@ explain select a from t1;
 select a from t1;
 drop table t1;
 
+#
+# bug#2686 - index_merge select on BerkeleyDB table with varchar PK causes mysqld to crash
+#
+
+create table t1(
+  pk1 text not null, pk2 text not null, pk3 char(4),
+  key1 int, key2 int,
+  primary key(pk1(4), pk2(4), pk3), key(key1), key(key2)
+) engine=bdb;
+insert into t1 values (concat('aaa-', repeat('A', 4000)),
+  concat('eee-', repeat('e', 4000)), 'a++a', 1, 1);
+insert into t1 values (concat('bbb-', repeat('B', 4000)),
+  concat('ggg-', repeat('G', 4000)), 'b++b', 1, 1);
+select substring(pk1, 1, 4), substring(pk1, 4001),
+       substring(pk2, 1, 4), substring(pk2, 4001), pk3, key1, key2
+       from t1 force index(key1, key2) where key1 < 3 or key2 < 3;
+drop table t1;
+
+
 #
 # bug#2688 - Wrong index_merge query results for BDB table with variable length primary key
 #

sql/field.cc

@@ -4167,6 +4167,42 @@ uint32 Field_blob::get_length(const char *pos)
 }
 
 
+/*
+  Put a blob length field into a record buffer.
+
+  SYNOPSIS
+    Field_blob::put_length()
+    pos                         Pointer into the record buffer.
+    length                      The length value to put.
+
+  DESCRIPTION
+    Depending on the maximum length of a blob, its length field is
+    put into 1 to 4 bytes. This is a property of the blob object,
+    described by 'packlength'.
+
+  RETURN
+    nothing
+*/
+
+void Field_blob::put_length(char *pos, uint32 length)
+{
+  switch (packlength) {
+  case 1:
+    *pos= (char) length;
+    break;
+  case 2:
+    int2store(pos, length);
+    break;
+  case 3:
+    int3store(pos, length);
+    break;
+  case 4:
+    int4store(pos, length);
+    break;
+  }
+}
+
+
 void Field_blob::store(const char *from,uint len)
 {
   if (!len)
@@ -4525,6 +4561,50 @@ char *Field_blob::pack_key(char *to, const char *from, uint max_length)
   return to+length;
 }
 
+
+/*
+  Unpack a blob key into a record buffer.
+
+  SYNOPSIS
+    Field_blob::unpack_key()
+    to                          Pointer into the record buffer.
+    from                        Pointer to the packed key.
+    max_length                  Key length limit from key description.
+
+  DESCRIPTION
+    A blob key has a maximum size of 64K-1.
+    In its packed form, the length field is one or two bytes long,
+    depending on 'max_length'.
+    Depending on the maximum length of a blob, its length field is
+    put into 1 to 4 bytes. This is a property of the blob object,
+    described by 'packlength'.
+    Blobs are internally stored apart from the record buffer, which
+    contains a pointer to the blob buffer.
+
+  RETURN
+    Pointer into 'from' past the last byte copied from packed key.
+*/
+
+const char *Field_blob::unpack_key(char *to, const char *from, uint max_length)
+{
+  /* get length of the blob key */
+  uint32 length= *((uchar*) from++);
+  if (max_length > 255)
+    length+= (*((uchar*) from++)) << 8;
+
+  /* put the length into the record buffer */
+  put_length(to, length);
+
+  /* put the address of the blob buffer or NULL */
+  if (length)
+    memcpy_fixed(to + packlength, &from, sizeof(from));
+  else
+    bzero(to + packlength, sizeof(from));
+
+  /* point to first byte of next field in 'from' */
+  return from + length;
+}
+
 /* Create a packed key that will be used for storage from a MySQL key */
 
 char *Field_blob::pack_key_from_key_image(char *to, const char *from,

sql/field.h

@@ -189,6 +189,10 @@ class Field {
   {
     return pack(to,from,max_length);
   }
+  virtual const char *unpack_key(char* to, const char *from, uint max_length)
+  {
+    return unpack(to,from);
+  }
   virtual uint packed_col_length(const char *to, uint length)
   { return length;}
   virtual uint max_packed_col_length(uint max_length)
@@ -890,6 +894,7 @@ class Field_blob :public Field_str {
   inline uint32 get_length(uint row_offset=0)
   { return get_length(ptr+row_offset); }
   uint32 get_length(const char *ptr);
+  void put_length(char *pos, uint32 length);
   bool binary() const { return binary_flag; }
   inline void get_ptr(char **str)
     {
@@ -923,6 +928,7 @@ class Field_blob :public Field_str {
   const char *unpack(char *to, const char *from);
   char *pack_key(char *to, const char *from, uint max_length);
   char *pack_key_from_key_image(char* to, const char *from, uint max_length);
+  const char *unpack_key(char* to, const char *from, uint max_length);
   int pack_cmp(const char *a, const char *b, uint key_length);
   int pack_cmp(const char *b, uint key_length);
   uint packed_col_length(const char *col_ptr, uint length);

sql/ha_berkeley.cc

@@ -720,8 +720,8 @@ void ha_berkeley::unpack_key(char *record, DBT *key, uint index)
       }
       record[key_part->null_offset]&= ~key_part->null_bit;
     }
-    pos= (char*) key_part->field->unpack(record + key_part->field->offset(),
-					 pos);
+    pos= (char*) key_part->field->unpack_key(record + key_part->field->offset(),
+                                             pos, key_part->length);
   }
 }