Fix result of ROW_COUNT() after 'EXECUTE prepstmt'. (Bug #14956)

mysql-test/r/ps.result:
  Add new results
mysql-test/t/ps.test:
  Add new test
sql/sql_parse.cc:
  Don't reset row_count after processing EXECUTE statement.

mysql-test/r/ps.result

@@ -806,3 +806,10 @@ execute stmt;
 @@tx_isolation
 REPEATABLE-READ
 deallocate prepare stmt;
+create table t1 (id int);
+prepare ins_call from "insert into t1 (id) values (1)";
+execute ins_call;
+select row_count();
+row_count()
+1
+drop table t1;

mysql-test/t/ps.test

@@ -843,3 +843,15 @@ execute stmt;
 deallocate prepare stmt;
 
 # End of 4.1 tests
+
+#
+# Bug #14956: ROW_COUNT() returns incorrect result after EXECUTE of prepared
+# statement
+#
+create table t1 (id int);
+prepare ins_call from "insert into t1 (id) values (1)";
+execute ins_call;
+select row_count();
+drop table t1;
+
+# End of 5.0 tests

sql/sql_parse.cc

@@ -4822,11 +4822,15 @@ mysql_execute_command(THD *thd)
 
 
   /*
-    The return value for ROW_COUNT() is "implementation dependent" if
-    the statement is not DELETE, INSERT or UPDATE (or a CALL executing
-    such a statement), but -1 is what JDBC and ODBC wants.
+    The return value for ROW_COUNT() is "implementation dependent" if the
+    statement is not DELETE, INSERT or UPDATE, but -1 is what JDBC and ODBC
+    wants.
+
+    We do not change the value for a CALL or EXECUTE statement, so the value
+    generated by the last called (or executed) statement is preserved.
    */
-  if (lex->sql_command != SQLCOM_CALL && uc_update_queries[lex->sql_command]<2)
+  if (lex->sql_command != SQLCOM_CALL && lex->sql_command != SQLCOM_EXECUTE &&
+      uc_update_queries[lex->sql_command]<2)
     thd->row_count_func= -1;
   goto cleanup;