Bug #20103: Escaping with backslash does not work

- make the client to respect the server-side 
   no_backslash_escapes option and disable the 
   special meaning of backslash also at client side.

client/mysql.cc

@@ -1221,7 +1221,8 @@ static bool add_line(String &buffer,char *line,char *in_string,
       continue;
     }
 #endif
-    if (!*ml_comment && inchar == '\\')
+    if (!*ml_comment && inchar == '\\' &&
+        !(mysql.server_status & SERVER_STATUS_NO_BACKSLASH_ESCAPES))
     {
       // Found possbile one character command like \c
 

mysql-test/r/mysql_client.result

@@ -2,3 +2,7 @@
 1
 ERROR 1064 (42000) at line 3: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '' at line 1
 ERROR at line 1: USE must be followed by a database name
+\
+\\
+';
+';

mysql-test/t/mysql_client.test

@@ -27,3 +27,14 @@
 # client comment recognized, but parameter missing => error
 --exec echo "use"         >  $MYSQLTEST_VARDIR/tmp/bug20432.sql
 --exec $MYSQL              < $MYSQLTEST_VARDIR/tmp/bug20432.sql 2>&1
+
+#
+# Bug #20103: Escaping with backslash does not work
+#
+--exec echo "SET SQL_MODE = 'NO_BACKSLASH_ESCAPES';"  > $MYSQLTEST_VARDIR/tmp/bug20103.sql
+--exec echo "SELECT '\';" >> $MYSQLTEST_VARDIR/tmp/bug20103.sql
+--exec $MYSQL < $MYSQLTEST_VARDIR/tmp/bug20103.sql 2>&1
+
+--exec echo "SET SQL_MODE = '';"  > $MYSQLTEST_VARDIR/tmp/bug20103.sql
+--exec echo "SELECT '\';';" >> $MYSQLTEST_VARDIR/tmp/bug20103.sql
+--exec $MYSQL              < $MYSQLTEST_VARDIR/tmp/bug20103.sql 2>&1