Bug#8235 Connection collation change & table create with default result in crash

mysql-test/r/ctype_ucs.result:
  Test case
mysql-test/t/ctype_ucs.test:
  Test case
sql/field.cc:
  Fixed minus check to be UCS2-compatible
strings/ctype-ucs2.c:
  Missing my_scan_ucs2() was added.

mysql-test/r/ctype_ucs.result

@@ -613,3 +613,17 @@ ucs2_bin	00610009
 ucs2_bin	0061
 ucs2_bin	00610020
 drop table t1;
+SET NAMES latin1;
+SET collation_connection='ucs2_swedish_ci';
+CREATE TABLE t1 (Field1 int(10) default '0');
+INSERT INTO t1 VALUES ('-1');
+SELECT * FROM t1;
+Field1
+-1
+DROP TABLE t1;
+CREATE TABLE t1 (Field1 int(10) unsigned default '0');
+INSERT INTO t1 VALUES ('-1');
+Warnings:
+Warning	1265	Data truncated for column 'Field1' at row 1
+DROP TABLE t1;
+SET NAMES latin1;

mysql-test/t/ctype_ucs.test

@@ -390,3 +390,24 @@ SET collation_connection='ucs2_general_ci';
 SET NAMES latin1;
 SET collation_connection='ucs2_bin';
 -- source include/ctype_filesort.inc
+
+SET NAMES latin1;
+#
+# Bug#8235
+#
+# This bug also helped to find another problem that
+# INSERT of a UCS2 string containing a negative number
+# into a unsigned int column didn't produce warnings.
+# This test covers both problems.
+#
+SET collation_connection='ucs2_swedish_ci';
+CREATE TABLE t1 (Field1 int(10) default '0');
+# no warnings, negative numbers are allowed
+INSERT INTO t1 VALUES ('-1');
+SELECT * FROM t1;
+DROP TABLE t1;
+CREATE TABLE t1 (Field1 int(10) unsigned default '0');
+# this should generate a "Data truncated" warning
+INSERT INTO t1 VALUES ('-1');
+DROP TABLE t1;
+SET NAMES latin1;

sql/field.cc

@@ -1777,6 +1777,14 @@ void Field_medium::sql_type(String &res) const
 ****************************************************************************/
 
 
+static bool test_if_minus(CHARSET_INFO *cs,
+                          const char *s, const char *e)
+{
+  my_wc_t wc;
+  return cs->cset->mb_wc(cs, &wc, (uchar*) s, (uchar*) e) > 0 && wc == '-';
+}
+
+
 int Field_long::store(const char *from,uint len,CHARSET_INFO *cs)
 {
   long tmp;
@@ -1790,7 +1798,7 @@ int Field_long::store(const char *from,uint len,CHARSET_INFO *cs)
 
   if (unsigned_flag)
   {
-    if (!len || *from == '-')
+    if (!len || test_if_minus(cs, from, from + len))
     {
       tmp=0;					// Set negative to 0
       my_errno=ERANGE;
@@ -2086,7 +2094,7 @@ int Field_longlong::store(const char *from,uint len,CHARSET_INFO *cs)
   my_errno=0;
   if (unsigned_flag)
   {
-    if (!len || *from == '-')
+    if (!len || test_if_minus(cs, from, from + len))
     {
       tmp=0;					// Set negative to 0
       my_errno= ERANGE;

strings/ctype-ucs2.c

@@ -1480,6 +1480,29 @@ my_bool my_like_range_ucs2(CHARSET_INFO *cs,
   return 0;
 }
 
+
+ulong my_scan_ucs2(CHARSET_INFO *cs __attribute__((unused)),
+                   const char *str, const char *end, int sequence_type)
+{
+  const char *str0= str;
+  end--; /* for easier loop condition, because of two bytes per character */
+  
+  switch (sequence_type)
+  {
+  case MY_SEQ_SPACES:
+    for ( ; str < end; str+= 2)
+    {
+      if (str[0] != '\0' || str[1] != ' ')
+        break;
+    }
+    return str - str0;
+  default:
+    return 0;
+  }
+}
+
+
+
 static MY_COLLATION_HANDLER my_collation_ucs2_general_ci_handler =
 {
     NULL,		/* init */
@@ -1534,7 +1557,7 @@ MY_CHARSET_HANDLER my_charset_ucs2_handler=
     my_strntoull_ucs2,
     my_strntod_ucs2,
     my_strtoll10_ucs2,
-    my_scan_8bit
+    my_scan_ucs2
 };