Bug #26207: When making the key image to use

 in index search MySQL was not explicitly
 suppressing warnings. And if the context 
 happens to enable warnings (e.g. INSERT ..
 SELECT) the warnings resulting from converting 
 the data the key is compared to are 
 reported to the client.
 Fixed by suppressing warnings when converting
 the data to the same type as the key parts.

mysql-test/r/insert_select.result

@@ -744,3 +744,32 @@ f1	f2
 2	2
 10	10
 DROP TABLE t1, t2;
+SET SQL_MODE='STRICT_TRANS_TABLES,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION';
+CREATE TABLE t1 (c VARCHAR(30), INDEX ix_c (c(10)));
+CREATE TABLE t2 (d VARCHAR(10));
+INSERT INTO t1 (c) VALUES ('7_chars'), ('13_characters');
+EXPLAIN
+SELECT (SELECT SUM(LENGTH(c)) FROM t1 WHERE c='13_characters') FROM t1;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	
+2	SUBQUERY	t1	ref	ix_c	ix_c	13	const	1	Using where
+SELECT (SELECT SUM(LENGTH(c)) FROM t1 WHERE c='13_characters') FROM t1;
+(SELECT SUM(LENGTH(c)) FROM t1 WHERE c='13_characters')
+13
+13
+INSERT INTO t2 (d) 
+SELECT (SELECT SUM(LENGTH(c)) FROM t1 WHERE c='13_characters') FROM t1;
+INSERT INTO t2 (d) 
+SELECT (SELECT SUM(LENGTH(c)) FROM t1 WHERE c='7_chars') FROM t1;
+INSERT INTO t2 (d)
+SELECT (SELECT SUM(LENGTH(c)) FROM t1 WHERE c IN (SELECT t1.c FROM t1)) 
+FROM t1;
+SELECT * FROM t2;
+d
+13
+13
+7
+7
+20
+20
+DROP TABLE t1,t2;

mysql-test/t/insert_select.test

@@ -306,4 +306,29 @@ INSERT INTO t2 (f1, f2)
 SELECT * FROM t2;
 DROP TABLE t1, t2;
 
+#
+# Bug #26207: inserts don't work with shortened index
+#
+SET SQL_MODE='STRICT_TRANS_TABLES,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION';
+
+CREATE TABLE t1 (c VARCHAR(30), INDEX ix_c (c(10)));
+CREATE TABLE t2 (d VARCHAR(10)); 
+INSERT INTO t1 (c) VALUES ('7_chars'), ('13_characters'); 
+
+EXPLAIN
+  SELECT (SELECT SUM(LENGTH(c)) FROM t1 WHERE c='13_characters') FROM t1;
+
+SELECT (SELECT SUM(LENGTH(c)) FROM t1 WHERE c='13_characters') FROM t1;
 
+INSERT INTO t2 (d) 
+  SELECT (SELECT SUM(LENGTH(c)) FROM t1 WHERE c='13_characters') FROM t1;
+
+INSERT INTO t2 (d) 
+  SELECT (SELECT SUM(LENGTH(c)) FROM t1 WHERE c='7_chars') FROM t1;
+
+INSERT INTO t2 (d)
+  SELECT (SELECT SUM(LENGTH(c)) FROM t1 WHERE c IN (SELECT t1.c FROM t1)) 
+  FROM t1;
+
+SELECT * FROM t2;
+DROP TABLE t1,t2;

sql/sql_select.h

@@ -488,15 +488,11 @@ extern "C" int refpos_order_cmp(void* arg, const void *a,const void *b);
 
 class store_key :public Sql_alloc
 {
- protected:
-  Field *to_field;				// Store data here
-  char *null_ptr;
-  char err;
 public:
   bool null_key; /* TRUE <=> the value of the key has a null part */
   enum store_key_result { STORE_KEY_OK, STORE_KEY_FATAL, STORE_KEY_CONV };
   store_key(THD *thd, Field *field_arg, char *ptr, char *null, uint length)
-    :null_ptr(null), err(0), null_key(0)
+    :null_key(0), null_ptr(null), err(0)
   {
     if (field_arg->type() == FIELD_TYPE_BLOB)
     {
@@ -510,8 +506,35 @@ class store_key :public Sql_alloc
                                         ptr, (uchar*) null, 1);
   }
   virtual ~store_key() {}			/* Not actually needed */
-  virtual enum store_key_result copy()=0;
   virtual const char *name() const=0;
+
+  /**
+    @brief sets ignore truncation warnings mode and calls the real copy method
+
+    @details this function makes sure truncation warnings when preparing the
+    key buffers don't end up as errors (because of an enclosing INSERT/UPDATE).
+  */
+  enum store_key_result copy()
+  {
+    enum store_key_result result;
+    enum_check_fields saved_count_cuted_fields= 
+      to_field->table->in_use->count_cuted_fields;
+
+    to_field->table->in_use->count_cuted_fields= CHECK_FIELD_IGNORE;
+
+    result= copy_inner();
+
+    to_field->table->in_use->count_cuted_fields= saved_count_cuted_fields;
+
+    return result;
+  }
+
+ protected:
+  Field *to_field;				// Store data here
+  char *null_ptr;
+  char err;
+
+  virtual enum store_key_result copy_inner()=0;
 };
 
 
@@ -531,13 +554,15 @@ class store_key_field: public store_key
       copy_field.set(to_field,from_field,0);
     }
   }
-  enum store_key_result copy()
+  const char *name() const { return field_name; }
+
+ protected: 
+  enum store_key_result copy_inner()
   {
     copy_field.do_copy(&copy_field);
     null_key= to_field->is_null();
     return err != 0 ? STORE_KEY_FATAL : STORE_KEY_OK;
   }
-  const char *name() const { return field_name; }
 };
 
 
@@ -552,13 +577,15 @@ class store_key_item :public store_key
 	       null_ptr_arg ? null_ptr_arg : item_arg->maybe_null ?
 	       &err : NullS, length), item(item_arg)
   {}
-  enum store_key_result copy()
+  const char *name() const { return "func"; }
+
+ protected:  
+  enum store_key_result copy_inner()
   {
     int res= item->save_in_field(to_field, 1);
     null_key= to_field->is_null() || item->null_value;
     return (err != 0 || res > 2 ? STORE_KEY_FATAL : (store_key_result) res); 
   }
-  const char *name() const { return "func"; }
 };
 
 
@@ -574,7 +601,10 @@ class store_key_const_item :public store_key_item
 		    &err : NullS, length, item_arg), inited(0)
   {
   }
-  enum store_key_result copy()
+  const char *name() const { return "const"; }
+
+protected:  
+  enum store_key_result copy_inner()
   {
     int res;
     if (!inited)
@@ -589,7 +619,6 @@ class store_key_const_item :public store_key_item
     null_key= to_field->is_null() || item->null_value;
     return (err > 2 ?  STORE_KEY_FATAL : (store_key_result) err);
   }
-  const char *name() const { return "const"; }
 };
 
 bool cp_buffer_from_ref(THD *thd, TABLE_REF *ref);