MDEV-10191 non convertible chars convert() resulted in Null instead "?" on Windows

The problem was introduced by the patch for MDEV-7661,
which (in addition to the fix itself) included an attempt to make
CONVERT/CAST work in the same way with fields
(i.e. return NULL in strict mode if a non-convertable character found).
It appeared to be a bad idea and some users were affected by this
behavior change. Changing CONVERT/CAST not depend on sql_mode
(restoring pre-10.1.4 behavior).

6 files changed, 47 insertions, 10 deletions

diff --git a/mysql-test/r/ctype_utf8.result b/mysql-test/r/ctype_utf8.result
index 2960b648b84..2b53f43cfc9 100644
--- a/mysql-test/r/ctype_utf8.result
+++ b/mysql-test/r/ctype_utf8.result
@@ -1945,7 +1945,7 @@ Warnings:
 Warning	1300	Invalid utf8 character string: 'FD'
 select convert(char(0xff,0x8f) using utf8);
 convert(char(0xff,0x8f) using utf8)
-NULL
+??
 Warnings:
 Warning	1300	Invalid utf8 character string: '\xFF\x8F'
 select hex(convert(char(2557 using latin1) using utf8));
@@ -2114,7 +2114,7 @@ Warnings:
 Warning	1300	Invalid utf8 character string: 'FF'
 select hex(convert(0xFF using utf8));
 hex(convert(0xFF using utf8))
-NULL
+3F
 Warnings:
 Warning	1300	Invalid utf8 character string: '\xFF'
 select hex(_utf8 0x616263FF);
@@ -10473,5 +10473,30 @@ END
 DROP PROCEDURE p1;
 SET @@SQL_MODE=default;
 #
+# MDEV-10191 non convertible chars convert() resulted in Null instead "?" on Windows
+#
+SET sql_mode='STRICT_TRANS_TABLES';
+SELECT CONVERT(_utf8 0xC499 USING latin1);
+CONVERT(_utf8 0xC499 USING latin1)
+?
+Warnings:
+Warning	1977	Cannot convert 'utf8' character 0xC499 to 'latin1'
+SELECT CAST(_utf8 0xC499 AS CHAR CHARACTER SET latin1);
+CAST(_utf8 0xC499 AS CHAR CHARACTER SET latin1)
+?
+Warnings:
+Warning	1977	Cannot convert 'utf8' character 0xC499 to 'latin1'
+SET sql_mode=default;
+SELECT CONVERT(_utf8 0xC499 USING latin1);
+CONVERT(_utf8 0xC499 USING latin1)
+?
+Warnings:
+Warning	1977	Cannot convert 'utf8' character 0xC499 to 'latin1'
+SELECT CAST(_utf8 0xC499 AS CHAR CHARACTER SET latin1);
+CAST(_utf8 0xC499 AS CHAR CHARACTER SET latin1)
+?
+Warnings:
+Warning	1977	Cannot convert 'utf8' character 0xC499 to 'latin1'
+#
 # End of 10.1 tests
 #
diff --git a/mysql-test/r/ctype_utf8mb4.result b/mysql-test/r/ctype_utf8mb4.result
index dd1c5249bc7..bac0fc34f80 100644
--- a/mysql-test/r/ctype_utf8mb4.result
+++ b/mysql-test/r/ctype_utf8mb4.result
@@ -1970,7 +1970,7 @@ Warnings:
 Warning	1300	Invalid utf8mb4 character string: 'FD'
 select convert(char(0xff,0x8f) using utf8mb4);
 convert(char(0xff,0x8f) using utf8mb4)
-NULL
+??
 Warnings:
 Warning	1300	Invalid utf8mb4 character string: '\xFF\x8F'
 select hex(convert(char(2557 using latin1) using utf8mb4));
@@ -2139,7 +2139,7 @@ Warnings:
 Warning	1300	Invalid utf8mb4 character string: 'FF'
 select hex(convert(0xFF using utf8mb4));
 hex(convert(0xFF using utf8mb4))
-NULL
+3F
 Warnings:
 Warning	1300	Invalid utf8mb4 character string: '\xFF'
 select hex(_utf8mb4 0x616263FF);
diff --git a/mysql-test/r/ctype_utf8mb4_heap.result b/mysql-test/r/ctype_utf8mb4_heap.result
index d70e009228e..46b0cc3789f 100644
--- a/mysql-test/r/ctype_utf8mb4_heap.result
+++ b/mysql-test/r/ctype_utf8mb4_heap.result
@@ -1802,7 +1802,7 @@ Warnings:
 Warning	1300	Invalid utf8mb4 character string: 'FD'
 select convert(char(0xff,0x8f) using utf8mb4);
 convert(char(0xff,0x8f) using utf8mb4)
-NULL
+??
 Warnings:
 Warning	1300	Invalid utf8mb4 character string: '\xFF\x8F'
 select hex(convert(char(2557 using latin1) using utf8mb4));
@@ -1971,7 +1971,7 @@ Warnings:
 Warning	1300	Invalid utf8mb4 character string: 'FF'
 select hex(convert(0xFF using utf8mb4));
 hex(convert(0xFF using utf8mb4))
-NULL
+3F
 Warnings:
 Warning	1300	Invalid utf8mb4 character string: '\xFF'
 select hex(_utf8mb4 0x616263FF);
diff --git a/mysql-test/r/ctype_utf8mb4_innodb.result b/mysql-test/r/ctype_utf8mb4_innodb.result
index 7d193f397ac..cfd9bf969ad 100644
--- a/mysql-test/r/ctype_utf8mb4_innodb.result
+++ b/mysql-test/r/ctype_utf8mb4_innodb.result
@@ -1930,7 +1930,7 @@ Warnings:
 Warning	1300	Invalid utf8mb4 character string: 'FD'
 select convert(char(0xff,0x8f) using utf8mb4);
 convert(char(0xff,0x8f) using utf8mb4)
-NULL
+??
 Warnings:
 Warning	1300	Invalid utf8mb4 character string: '\xFF\x8F'
 select hex(convert(char(2557 using latin1) using utf8mb4));
@@ -2099,7 +2099,7 @@ Warnings:
 Warning	1300	Invalid utf8mb4 character string: 'FF'
 select hex(convert(0xFF using utf8mb4));
 hex(convert(0xFF using utf8mb4))
-NULL
+3F
 Warnings:
 Warning	1300	Invalid utf8mb4 character string: '\xFF'
 select hex(_utf8mb4 0x616263FF);
diff --git a/mysql-test/r/ctype_utf8mb4_myisam.result b/mysql-test/r/ctype_utf8mb4_myisam.result
index 28cf36c7492..53ae410046f 100644
--- a/mysql-test/r/ctype_utf8mb4_myisam.result
+++ b/mysql-test/r/ctype_utf8mb4_myisam.result
@@ -1930,7 +1930,7 @@ Warnings:
 Warning	1300	Invalid utf8mb4 character string: 'FD'
 select convert(char(0xff,0x8f) using utf8mb4);
 convert(char(0xff,0x8f) using utf8mb4)
-NULL
+??
 Warnings:
 Warning	1300	Invalid utf8mb4 character string: '\xFF\x8F'
 select hex(convert(char(2557 using latin1) using utf8mb4));
@@ -2099,7 +2099,7 @@ Warnings:
 Warning	1300	Invalid utf8mb4 character string: 'FF'
 select hex(convert(0xFF using utf8mb4));
 hex(convert(0xFF using utf8mb4))
-NULL
+3F
 Warnings:
 Warning	1300	Invalid utf8mb4 character string: '\xFF'
 select hex(_utf8mb4 0x616263FF);
diff --git a/mysql-test/t/ctype_utf8.test b/mysql-test/t/ctype_utf8.test
index 5f1de609df1..e6792922b95 100644
--- a/mysql-test/t/ctype_utf8.test
+++ b/mysql-test/t/ctype_utf8.test
@@ -1983,6 +1983,18 @@ SET @@SQL_MODE=default;
 #DROP FUNCTION f1;
 #SET NAMES utf8;
 
+--echo #
+--echo # MDEV-10191 non convertible chars convert() resulted in Null instead "?" on Windows
+--echo #
+
+SET sql_mode='STRICT_TRANS_TABLES';
+SELECT CONVERT(_utf8 0xC499 USING latin1);
+SELECT CAST(_utf8 0xC499 AS CHAR CHARACTER SET latin1);
+
+SET sql_mode=default;
+SELECT CONVERT(_utf8 0xC499 USING latin1);
+SELECT CAST(_utf8 0xC499 AS CHAR CHARACTER SET latin1);
+
 
 --echo #
 --echo # End of 10.1 tests