Produce a "truncated" warning if a value cannot be converted

into the column character set on INSERT/UPDATE.

mysql-test/r/alter_table.result

@@ -349,6 +349,7 @@ alter table t1 change a a char(10) character set koi8r;
 select a,hex(a) from t1;
 a	hex(a)
 	D4C5D3D4
+delete from t1;
 show create table t1;
 Table	Create Table
 t1	CREATE TABLE `t1` (

mysql-test/r/ctype_recoding.result

@@ -166,3 +166,11 @@ ERROR HY000: Invalid utf8 character string: '
 SET NAMES utf8;
 CREATE TABLE `good` (a int);
 ERROR HY000: Invalid utf8 character string: '` (a int)'
+set names latin1;
+create table t1 (a char(10) character set koi8r, b text character set koi8r);
+insert into t1 values ('test','test');
+insert into t1 values ('','');
+Warnings:
+Warning	1265	Data truncated for column 'a' at row 1
+Warning	1265	Data truncated for column 'b' at row 1
+drop table t1;

mysql-test/r/fulltext.result

@@ -356,6 +356,11 @@ SELECT t, collation(t),MATCH t AGAINST ('Osnabruck') FROM t1 WHERE MATCH t AGAIN
 t	collation(t)	MATCH t AGAINST ('Osnabruck')
 aus Osnabrck	utf8_general_ci	1.591139793396
 alter table t1 modify t varchar(200) collate latin1_german2_ci not null;
+Warnings:
+Warning	1265	Data truncated for column 't' at row 3
+Warning	1265	Data truncated for column 't' at row 4
+Warning	1265	Data truncated for column 't' at row 5
+Warning	1265	Data truncated for column 't' at row 6
 SELECT t, collation(t) FROM t1 WHERE MATCH t AGAINST ('Osnabrck');
 t	collation(t)
 aus Osnabrck	latin1_german2_ci

mysql-test/t/alter_table.test

@@ -207,6 +207,7 @@ alter table t1 change a a text character set cp1251;
 select a,hex(a) from t1;
 alter table t1 change a a char(10) character set koi8r;
 select a,hex(a) from t1;
+delete from t1;
 
 #
 # Test ALTER TABLE .. CHARACTER SET ..

mysql-test/t/ctype_recoding.test

@@ -121,3 +121,13 @@ CREATE TABLE `good
 SET NAMES utf8;
 --error 1300
 CREATE TABLE `good` (a int);
+
+
+#
+# Test that we produce a warnign when conversion loses data.
+#
+set names latin1;
+create table t1 (a char(10) character set koi8r, b text character set koi8r);
+insert into t1 values ('test','test');
+insert into t1 values ('','');
+drop table t1;

sql/field.cc

@@ -4275,9 +4275,12 @@ int Field_string::store(const char *from,uint length,CHARSET_INFO *cs)
   /* Convert character set if nesessary */
   if (String::needs_conversion(length, cs, field_charset, &not_used))
   { 
-    tmpstr.copy(from, length, cs, field_charset);
+    uint conv_errors;
+    tmpstr.copy(from, length, cs, field_charset, &conv_errors);
     from= tmpstr.ptr();
     length=  tmpstr.length();
+    if (conv_errors)
+      error= 1;
   }
 
   /* 
@@ -4300,11 +4303,11 @@ int Field_string::store(const char *from,uint length,CHARSET_INFO *cs)
     from+= field_charset->cset->scan(field_charset, from, end,
 				     MY_SEQ_SPACES);
     if (from != end)
-    {
-      set_warning(MYSQL_ERROR::WARN_LEVEL_WARN, ER_WARN_DATA_TRUNCATED, 1);
-      error=1;
-    }
+      error= 1;
   }
+  if (error)
+    set_warning(MYSQL_ERROR::WARN_LEVEL_WARN, ER_WARN_DATA_TRUNCATED, 1);
+
   return error;
 }
 
@@ -4528,16 +4531,20 @@ int Field_varstring::store(const char *from,uint length,CHARSET_INFO *cs)
   /* Convert character set if nesessary */
   if (String::needs_conversion(length, cs, field_charset, &not_used))
   { 
-    tmpstr.copy(from, length, cs, field_charset);
+    uint conv_errors;
+    tmpstr.copy(from, length, cs, field_charset, &conv_errors);
     from= tmpstr.ptr();
     length=  tmpstr.length();
+    if (conv_errors)
+      error= 1;
   }
   if (length > field_length)
   {
     length=field_length;
-    set_warning(MYSQL_ERROR::WARN_LEVEL_WARN, ER_WARN_DATA_TRUNCATED, 1);
     error= 1;
   }
+  if (error)
+    set_warning(MYSQL_ERROR::WARN_LEVEL_WARN, ER_WARN_DATA_TRUNCATED, 1);
   memcpy(ptr+HA_KEY_BLOB_LENGTH,from,length);
   int2store(ptr, length);
   return error;
@@ -4865,6 +4872,7 @@ void Field_blob::put_length(char *pos, uint32 length)
 
 int Field_blob::store(const char *from,uint length,CHARSET_INFO *cs)
 {
+  int error= 0;
   if (!length)
   {
     bzero(ptr,Field_blob::pack_length());
@@ -4881,9 +4889,12 @@ int Field_blob::store(const char *from,uint length,CHARSET_INFO *cs)
     if ((was_conversion= String::needs_conversion(length, cs, field_charset,
 						  &not_used)))
     { 
-      tmpstr.copy(from, length, cs, field_charset);
+      uint conv_errors;
+      tmpstr.copy(from, length, cs, field_charset, &conv_errors);
       from= tmpstr.ptr();
       length=  tmpstr.length();
+      if (conv_errors)
+        error= 1;
     }
     
     copy_length= max_data_length();
@@ -4897,8 +4908,7 @@ int Field_blob::store(const char *from,uint length,CHARSET_INFO *cs)
 						      min(length, copy_length),
 						      copy_length);
     if (copy_length < length)
-      set_warning(MYSQL_ERROR::WARN_LEVEL_WARN, ER_WARN_DATA_TRUNCATED, 1);
-    
+      error= 1;
     Field_blob::store_length(copy_length);
     if (was_conversion || table->copy_blobs || copy_length <= MAX_FIELD_WIDTH)
     {						// Must make a copy
@@ -4910,6 +4920,8 @@ int Field_blob::store(const char *from,uint length,CHARSET_INFO *cs)
     }
     bmove(ptr+packlength,(char*) &from,sizeof(char*));
   }
+  if (error)
+    set_warning(MYSQL_ERROR::WARN_LEVEL_WARN, ER_WARN_DATA_TRUNCATED, 1);
   return 0;
 }
 

sql/sql_string.cc

@@ -331,19 +331,26 @@ bool String::set_or_copy_aligned(const char *str,uint32 arg_length,
 	/* Copy with charset convertion */
 
 bool String::copy(const char *str, uint32 arg_length,
-		  CHARSET_INFO *from_cs, CHARSET_INFO *to_cs)
+		  CHARSET_INFO *from_cs, CHARSET_INFO *to_cs, uint *errors)
 {
   uint32 offset;
   if (!needs_conversion(arg_length, from_cs, to_cs, &offset))
+  {
+    if (errors)
+      *errors= 0;
     return copy(str, arg_length, to_cs);
+  }
   if ((from_cs == &my_charset_bin) && offset)
+  {
+    if (errors)
+      *errors= 0;
     return copy_aligned(str, arg_length, offset, to_cs);
-  
+  }
   uint32 new_length= to_cs->mbmaxlen*arg_length;
   if (alloc(new_length))
     return TRUE;
   str_length=copy_and_convert((char*) Ptr, new_length, to_cs,
-			      str, arg_length, from_cs);
+                              str, arg_length, from_cs, errors);
   str_charset=to_cs;
   return FALSE;
 }
@@ -769,7 +776,8 @@ String *copy_if_not_alloced(String *to,String *from,uint32 from_length)
 
 uint32
 copy_and_convert(char *to, uint32 to_length, CHARSET_INFO *to_cs, 
-		 const char *from, uint32 from_length, CHARSET_INFO *from_cs)
+                 const char *from, uint32 from_length, CHARSET_INFO *from_cs,
+                 uint *errors)
 {
   int         cnvres;
   my_wc_t     wc;
@@ -780,6 +788,7 @@ copy_and_convert(char *to, uint32 to_length, CHARSET_INFO *to_cs,
 	       const uchar *) = from_cs->cset->mb_wc;
   int (*wc_mb)(struct charset_info_st *, my_wc_t, uchar *s, uchar *e)=
     to_cs->cset->wc_mb;
+  uint error_count= 0;
 
   while (1)
   {
@@ -788,6 +797,7 @@ copy_and_convert(char *to, uint32 to_length, CHARSET_INFO *to_cs,
       from+= cnvres;
     else if (cnvres == MY_CS_ILSEQ)
     {
+      error_count++;
       from++;
       wc= '?';
     }
@@ -799,12 +809,15 @@ copy_and_convert(char *to, uint32 to_length, CHARSET_INFO *to_cs,
       to+= cnvres;
     else if (cnvres == MY_CS_ILUNI && wc != '?')
     {
+      error_count++;
       wc= '?';
       goto outp;
     }
     else
       break;
   }
+  if (errors)
+    *errors= error_count;
   return (uint32) (to - to_start);
 }
 

sql/sql_string.h

@@ -29,7 +29,7 @@ int sortcmp(const String *a,const String *b, CHARSET_INFO *cs);
 String *copy_if_not_alloced(String *a,String *b,uint32 arg_length);
 uint32 copy_and_convert(char *to, uint32 to_length, CHARSET_INFO *to_cs,
 			const char *from, uint32 from_length,
-			CHARSET_INFO *from_cs);
+			CHARSET_INFO *from_cs, uint *errors= 0);
 
 class String
 {
@@ -199,7 +199,7 @@ class String
 		    CHARSET_INFO *cs);
   bool set_or_copy_aligned(const char *s, uint32 arg_length, CHARSET_INFO *cs);
   bool copy(const char*s,uint32 arg_length, CHARSET_INFO *csfrom,
-	    CHARSET_INFO *csto);
+	    CHARSET_INFO *csto, uint *errors= 0);
   bool append(const String &s);
   bool append(const char *s);
   bool append(const char *s,uint32 arg_length);