From ef47b62551b0f37770e5d174ea028150c5b71fd8 Mon Sep 17 00:00:00 2001
From: Sergei Golubchik <serg@mariadb.org>
Date: Sat, 5 Dec 2015 11:29:00 +0100
Subject: [PATCH] MDEV-8827 Duplicate key with auto increment

fix innodb auto-increment handling
three bugs:
1. innobase_next_autoinc treated the case of current<offset incorrectly
2. ha_innobase::get_auto_increment didn't recalculate current when increment changed
3. ha_innobase::get_auto_increment didn't pass offset down to innobase_next_autoinc
---
 mysql-test/suite/innodb/r/innodb-autoinc.result |  4 ++--
 mysql-test/suite/innodb/t/innodb-autoinc.test   |  2 +-
 storage/innobase/handler/ha_innodb.cc           | 12 +++++-------
 storage/xtradb/handler/ha_innodb.cc             | 12 +++++-------
 4 files changed, 13 insertions(+), 17 deletions(-)

diff --git a/mysql-test/suite/innodb/r/innodb-autoinc.result b/mysql-test/suite/innodb/r/innodb-autoinc.result
index d6f7a930340..2ea6869291e 100644
--- a/mysql-test/suite/innodb/r/innodb-autoinc.result
+++ b/mysql-test/suite/innodb/r/innodb-autoinc.result
@@ -567,7 +567,7 @@ Variable_name	Value
 auto_increment_increment	65535
 auto_increment_offset	65535
 INSERT INTO t1 VALUES (NULL),(NULL);
-ERROR 22003: Out of range value for column 'c1' at row 1
+ERROR HY000: Failed to read auto-increment value from storage engine
 SELECT * FROM t1;
 c1
 1
@@ -660,7 +660,7 @@ t2	CREATE TABLE `t2` (
   `n` int(10) unsigned NOT NULL,
   `o` enum('FALSE','TRUE') DEFAULT NULL,
   PRIMARY KEY (`m`)
-) ENGINE=InnoDB AUTO_INCREMENT=19 DEFAULT CHARSET=latin1
+) ENGINE=InnoDB AUTO_INCREMENT=14 DEFAULT CHARSET=latin1
 INSERT INTO t1 (b,c) SELECT n,o FROM t2 ;
 SHOW CREATE TABLE t1;
 Table	Create Table
diff --git a/mysql-test/suite/innodb/t/innodb-autoinc.test b/mysql-test/suite/innodb/t/innodb-autoinc.test
index 5e5a2b49a7d..362be2e055b 100644
--- a/mysql-test/suite/innodb/t/innodb-autoinc.test
+++ b/mysql-test/suite/innodb/t/innodb-autoinc.test
@@ -349,7 +349,7 @@ INSERT INTO t1 VALUES (18446744073709551610); #-- 2^64 - 2
 SELECT * FROM t1;
 SET @@SESSION.AUTO_INCREMENT_INCREMENT=1152921504606846976, @@SESSION.AUTO_INCREMENT_OFFSET=1152921504606846976;
 SHOW VARIABLES LIKE "%auto_inc%";
---error 167
+--error 1467
 INSERT INTO t1 VALUES (NULL),(NULL);
 SELECT * FROM t1;
 DROP TABLE t1;
diff --git a/storage/innobase/handler/ha_innodb.cc b/storage/innobase/handler/ha_innodb.cc
index 17cf15e6b84..95216d30aae 100644
--- a/storage/innobase/handler/ha_innodb.cc
+++ b/storage/innobase/handler/ha_innodb.cc
@@ -1504,10 +1504,11 @@ innobase_next_autoinc(
 	if (next_value == 0) {
 		ulonglong	next;
 
-		if (current > offset) {
+		if (current >= offset) {
 			next = (current - offset) / step;
 		} else {
-			next = (offset - current) / step;
+			next = 0;
+			block -= step;
 		}
 
 		ut_a(max_value > next);
@@ -10445,15 +10446,12 @@ ha_innobase::get_auto_increment(
 
 		current = *first_value;
 
-		/* If the increment step of the auto increment column
-		decreases then it is not affecting the immediate
-		next value in the series. */
-		if (prebuilt->autoinc_increment > increment) {
+		if (prebuilt->autoinc_increment != increment) {
 
 			current = autoinc - prebuilt->autoinc_increment;
 
 			current = innobase_next_autoinc(
-				current, 1, increment, 1, col_max_value);
+				current, 1, increment, offset, col_max_value);
 
 			dict_table_autoinc_initialize(prebuilt->table, current);
 
diff --git a/storage/xtradb/handler/ha_innodb.cc b/storage/xtradb/handler/ha_innodb.cc
index b56cd4d5013..19aec80dbbd 100644
--- a/storage/xtradb/handler/ha_innodb.cc
+++ b/storage/xtradb/handler/ha_innodb.cc
@@ -1748,10 +1748,11 @@ innobase_next_autoinc(
 	if (next_value == 0) {
 		ulonglong	next;
 
-		if (current > offset) {
+		if (current >= offset) {
 			next = (current - offset) / step;
 		} else {
-			next = (offset - current) / step;
+			next = 0;
+			block -= step;
 		}
 
 		ut_a(max_value > next);
@@ -11604,15 +11605,12 @@ ha_innobase::get_auto_increment(
 
 		current = *first_value;
 
-		/* If the increment step of the auto increment column
-		decreases then it is not affecting the immediate
-		next value in the series. */
-		if (prebuilt->autoinc_increment > increment) {
+		if (prebuilt->autoinc_increment != increment) {
 
 			current = autoinc - prebuilt->autoinc_increment;
 
 			current = innobase_next_autoinc(
-				current, 1, increment, 1, col_max_value);
+				current, 1, increment, offset, col_max_value);
 
 			dict_table_autoinc_initialize(prebuilt->table, current);