Bug#14758405: ALTER TABLE: ADDING SERIAL NULL DATATYPE: ASSERTION:

LEN <= SIZEOF(ULONGLONG)

This bug was caught in the WL#6255 ALTER TABLE...ADD COLUMN in MySQL
5.6, but there is a bug in all InnoDB versions that support
auto-increment columns.

row_search_autoinc_read_column(): When reading the maximum value of
the auto-increment column, and the column only contains NULL values,
return 0. This corresponds to the case when the table is empty in
row_search_max_autoinc().

rb:1415 approved by Sunny Bains

storage/innobase/row/row0sel.c

@@ -4660,14 +4660,18 @@ row_search_autoinc_read_column(
 	/* TODO: We have to cast away the const of rec for now.  This needs
 	to be fixed later.*/
 	offsets = rec_get_offsets(
-		(rec_t*) rec, index, offsets, ULINT_UNDEFINED, &heap);
+		(rec_t*) rec, index, offsets, col_no + 1, &heap);
+
+	if (rec_offs_nth_sql_null(offsets, col_no)) {
+		/* There is no non-NULL value in the auto-increment column. */
+		value = 0;
+		goto func_exit;
+	}
 
 	/* TODO: We have to cast away the const of rec for now.  This needs
 	to be fixed later.*/
 	data = rec_get_nth_field((rec_t*)rec, offsets, col_no, &len);
 
-	ut_a(len != UNIV_SQL_NULL);
-
 	switch (mtype) {
 	case DATA_INT:
 		ut_a(len <= sizeof value);
@@ -4688,15 +4692,16 @@ row_search_autoinc_read_column(
 		ut_error;
 	}
 
-	if (UNIV_LIKELY_NULL(heap)) {
-		mem_heap_free(heap);
-	}
-
 	/* We assume that the autoinc counter can't be negative. */
 	if (!unsigned_type && (ib_longlong) value < 0) {
 		value = 0;
 	}
 
+func_exit:
+	if (UNIV_LIKELY_NULL(heap)) {
+		mem_heap_free(heap);
+	}
+
 	return(value);
 }
 

storage/innodb_plugin/ChangeLog

+2012-10-18	The InnoDB Team
+
+	* row/row0sel.c:
+	Fix Bug#14758405: ALTER TABLE: ADDING SERIAL NULL DATATYPE: ASSERTION:
+	LEN <= SIZEOF(ULONGLONG)
+
 2012-10-16	The InnoDB Team
 
 	* dict/dict0dict.c, handler/handler0alter.cc, include/dict0dict.h:

storage/innodb_plugin/row/row0sel.c

@@ -4833,11 +4833,15 @@ row_search_autoinc_read_column(
 
 	rec_offs_init(offsets_);
 
-	offsets = rec_get_offsets(rec, index, offsets, ULINT_UNDEFINED, &heap);
+	offsets = rec_get_offsets(rec, index, offsets, col_no + 1, &heap);
 
-	data = rec_get_nth_field(rec, offsets, col_no, &len);
+	if (rec_offs_nth_sql_null(offsets, col_no)) {
+		/* There is no non-NULL value in the auto-increment column. */
+		value = 0;
+		goto func_exit;
+	}
 
-	ut_a(len != UNIV_SQL_NULL);
+	data = rec_get_nth_field(rec, offsets, col_no, &len);
 
 	switch (mtype) {
 	case DATA_INT:
@@ -4859,14 +4863,15 @@ row_search_autoinc_read_column(
 		ut_error;
 	}
 
-	if (UNIV_LIKELY_NULL(heap)) {
-		mem_heap_free(heap);
-	}
-
 	if (!unsigned_type && (ib_int64_t) value < 0) {
 		value = 0;
 	}
 
+func_exit:
+	if (UNIV_LIKELY_NULL(heap)) {
+		mem_heap_free(heap);
+	}
+
 	return(value);
 }