Bug#45645 Mysql server close all connection and restart using lower function

Problem: the "caseinfo" member of CHARSET_INFO structure was not
initialized for user-defined Unicode collations, which made the
server crash.
Fix: initializing caseinfo properly.

mysql-test/r/ctype_ldml.result

@@ -41,6 +41,14 @@ efgh	efgh
 ijkl	ijkl
 DROP TABLE t1;
 #
+# Bug#45645 Mysql server close all connection and restart using lower function
+#
+CREATE TABLE t1 (a VARCHAR(10)) CHARACTER SET utf8 COLLATE utf8_test_ci;
+INSERT INTO t1 (a) VALUES ('hello!');
+SELECT * FROM t1 WHERE LOWER(a)=LOWER('N');
+a
+DROP TABLE t1;
+#
 # Bug#43827 Server closes connections and restarts
 #
 CREATE TABLE t1 (c1 VARCHAR(10) CHARACTER SET utf8 COLLATE utf8_test_ci);

mysql-test/t/ctype_ldml.test

@@ -37,6 +37,14 @@ UPDATE t1 SET col2=col1;
 SELECT * FROM t1 WHERE col1=col2 ORDER BY col1;
 DROP TABLE t1;
 
+--echo #
+--echo # Bug#45645 Mysql server close all connection and restart using lower function
+--echo #
+CREATE TABLE t1 (a VARCHAR(10)) CHARACTER SET utf8 COLLATE utf8_test_ci;
+INSERT INTO t1 (a) VALUES ('hello!');
+SELECT * FROM t1 WHERE LOWER(a)=LOWER('N');
+DROP TABLE t1;
+
 --echo #
 --echo # Bug#43827 Server closes connections and restarts
 --echo #

strings/ctype-uca.c

@@ -7858,6 +7858,8 @@ static my_bool create_tailoring(CHARSET_INFO *cs, void *(*alloc)(size_t))
     return 1;
   }
   
+  cs->caseinfo= my_unicase_default;
+  
   if (!(newweights= (uint16**) (*alloc)(256*sizeof(uint16*))))
     return 1;
   bzero(newweights, 256*sizeof(uint16*));