MDEV-13187 incorrect backslash parsing in clients

cover ANSI_QUOTES and NO_BACKSLASH_ESCAPES in mysqltest

client/mysql.cc

@@ -2288,6 +2288,8 @@ static bool add_line(String &buffer, char *line, ulong line_length,
     }
 #endif
     if (!*ml_comment && inchar == '\\' && *in_string != '`' &&
+        !(*in_string == '"' &&
+          (mysql.server_status & SERVER_STATUS_ANSI_QUOTES)) &&
         !(*in_string &&
           (mysql.server_status & SERVER_STATUS_NO_BACKSLASH_ESCAPES)))
     {

client/mysqltest.cc

@@ -6486,6 +6486,16 @@ my_bool end_of_query(int c)
 }
 
 
+static inline bool is_escape_char(char c, char in_string)
+{
+  if (c != '\\' || in_string == '`') return false;
+  if (!cur_con) return true;
+  uint server_status= cur_con->mysql->server_status;
+  if (server_status & SERVER_STATUS_NO_BACKSLASH_ESCAPES) return false;
+  return !(server_status & SERVER_STATUS_ANSI_QUOTES && in_string == '"');
+}
+
+
 /*
   Read one "line" from the file
 
@@ -6594,7 +6604,7 @@ int read_line(char *buf, int size)
 	  state= R_Q;
 	}
       }
-      have_slash= (c == '\\' && last_quote != '`');
+      have_slash= is_escape_char(c, last_quote);
       break;
 
     case R_COMMENT:
@@ -6664,7 +6674,7 @@ int read_line(char *buf, int size)
     case R_Q:
       if (c == last_quote)
 	state= R_NORMAL;
-      else if (c == '\\' && last_quote != '`')
+      else if (is_escape_char(c, last_quote))
 	state= R_SLASH_IN_Q;
       break;
 

include/mysql_com.h

@@ -296,6 +296,8 @@ enum enum_server_command
 */
 #define SERVER_PS_OUT_PARAMS            4096
 
+#define SERVER_STATUS_ANSI_QUOTES       32768
+
 /**
   Server status flags that must be cleared when starting
   execution of a new SQL statement.

mysql-test/r/mysql.result

@@ -557,3 +557,33 @@ a
 1
 2
 drop table `a1\``b1`;
+set sql_mode=ansi_quotes;
+create table "a1\""b1" (a int);
+show tables;
+Tables_in_test
+a1\"b1
+insert "a1\""b1" values (1),(2);
+show create table "a1\""b1";
+Table	Create Table
+a1\"b1	CREATE TABLE "a1\""b1" (
+  "a" int(11) DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+/*!40101 SET @saved_cs_client     = @@character_set_client */;
+/*!40101 SET character_set_client = utf8 */;
+CREATE TABLE "a1\""b1" (
+  "a" int(11) DEFAULT NULL
+);
+/*!40101 SET character_set_client = @saved_cs_client */;
+INSERT INTO "a1\""b1" VALUES (1),(2);
+insert "a1\""b1" values (4),(5);
+show create table "a1\""b1";
+Table	Create Table
+a1\"b1	CREATE TABLE "a1\""b1" (
+  "a" int(11) DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+select * from "a1\""b1";
+a
+1
+2
+drop table "a1\""b1";
+set sql_mode=default;

mysql-test/r/mysqltest.result

@@ -957,4 +957,9 @@ con1
 con2
 con2
 -closed_connection-
+set sql_mode=no_backslash_escapes;
+select "foo\""bar";
+foo\"bar
+foo\"bar
+set sql_mode=default;
 End of tests

mysql-test/t/mysql.test

@@ -633,3 +633,18 @@ insert `a1\``b1` values (4),(5);
 show create table `a1\``b1`;
 select * from `a1\``b1`;
 drop table `a1\``b1`;
+
+# same with ansi_quotes
+set sql_mode=ansi_quotes;
+create table "a1\""b1" (a int);
+show tables;
+insert "a1\""b1" values (1),(2);
+show create table "a1\""b1";
+--exec $MYSQL_DUMP --compact --compatible=postgres test
+--exec $MYSQL_DUMP --compatible=postgres test > $MYSQLTEST_VARDIR/tmp/bug.sql
+insert "a1\""b1" values (4),(5);
+--exec $MYSQL test < $MYSQLTEST_VARDIR/tmp/bug.sql
+show create table "a1\""b1";
+select * from "a1\""b1";
+drop table "a1\""b1";
+set sql_mode=default;

mysql-test/t/mysqltest.test

@@ -2942,11 +2942,17 @@ disconnect $x;
 # Disconnect the selected connection
 disconnect $y;
 --echo $CURRENT_CONNECTION
+connection default;
 
+#
+# MDEV-13187 incorrect backslash parsing in clients
+#
+set sql_mode=no_backslash_escapes;
+select "foo\""bar";
+set sql_mode=default;
 
 --echo End of tests
 
-connection default;
 # Wait till we reached the initial number of concurrent sessions
 --source include/wait_until_count_sessions.inc
 

sql/sql_class.cc

@@ -1250,6 +1250,8 @@ void THD::init(void)
   server_status= SERVER_STATUS_AUTOCOMMIT;
   if (variables.sql_mode & MODE_NO_BACKSLASH_ESCAPES)
     server_status|= SERVER_STATUS_NO_BACKSLASH_ESCAPES;
+  if (variables.sql_mode & MODE_ANSI_QUOTES)
+    server_status|= SERVER_STATUS_ANSI_QUOTES;
 
   transaction.all.modified_non_trans_table=
     transaction.stmt.modified_non_trans_table= FALSE;

sql/sys_vars.cc

@@ -2173,6 +2173,10 @@ static bool fix_sql_mode(sys_var *self, THD *thd, enum_var_type type)
       thd->server_status|= SERVER_STATUS_NO_BACKSLASH_ESCAPES;
     else
       thd->server_status&= ~SERVER_STATUS_NO_BACKSLASH_ESCAPES;
+    if (thd->variables.sql_mode & MODE_ANSI_QUOTES)
+      thd->server_status|= SERVER_STATUS_ANSI_QUOTES;
+    else
+      thd->server_status&= ~SERVER_STATUS_ANSI_QUOTES;
   }
   return false;
 }