Bug#19799 delimiter command not working correctly when sourcing a sql file

- Client side readline functions unconditionally search for Unix '\n' line
endings. In this case, the delimiter statement was set to '//\r' instead 
of the intended '//'. When removing the '\n' check for and remove 
preceeding '\r' character as well.

client/readline.cc

@@ -51,7 +51,8 @@ char *batch_readline(LINE_BUFFER *line_buff)
   if (!(pos=intern_read_line(line_buff,&out_length)))
     return 0;
   if (out_length && pos[out_length-1] == '\n')
-    out_length--;				/* Remove '\n' */
+    if (--out_length && pos[out_length-1] == '\r')  /* Remove '\n' */
+      out_length--;                                 /* Remove '\r' */
   line_buff->read_length=out_length;
   pos[out_length]=0;
   return pos;

mysql-test/r/mysql.result

@@ -36,6 +36,10 @@ Tables_in_test
 t1
 t2
 t3
+Database
+information_schema
+mysql
+test
 _
 Test delimiter : from command line
 a

mysql-test/t/mysql_delimiter.sql

@@ -49,3 +49,12 @@ delimiter ; # Reset delimiter
 # Bug #11523: \d works differently than delimiter
 #
 source t/mysql_delimiter_source.sql
+delimiter ; # Reset delimiter
+
+#
+# Bug #19799: delimiter command not working correctly when sourcing a sql file
+#             with Windows style line endings.
+#
+source t/mysql_delimiter_19799.sql
+show databases//
+delimiter ; # Reset delimiter

mysql-test/t/mysql_delimiter_19799.sql

@@ -0,0 +1 @@
+delimiter //