diff --git a/client/mysql.cc b/client/mysql.cc
index 36c9ada441c..a77901e5220 100644
--- a/client/mysql.cc
+++ b/client/mysql.cc
@@ -1230,7 +1230,8 @@ 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
 
diff --git a/mysql-test/r/mysql_client.result b/mysql-test/r/mysql_client.result
index 87d09428ff6..a20bd60aaf3 100644
--- a/mysql-test/r/mysql_client.result
+++ b/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
+\
+\\
+';
+';
diff --git a/mysql-test/r/view.result b/mysql-test/r/view.result
index a7d797773ce..2de47f44556 100644
--- a/mysql-test/r/view.result
+++ b/mysql-test/r/view.result
@@ -193,7 +193,7 @@ c	d
 2	5
 3	10
 drop view v100;
-ERROR 42S02: Unknown table 'test.v100'
+ERROR 42S02: Unknown table 'v100'
 drop view t1;
 ERROR HY000: 'test.t1' is not VIEW
 drop table v1;
@@ -2807,6 +2807,17 @@ yadda
 yad
 DROP VIEW v1;
 DROP TABLE t1;
+CREATE TABLE t1 (x INT, y INT);
+CREATE ALGORITHM=TEMPTABLE SQL SECURITY INVOKER VIEW v1 AS SELECT x FROM t1;
+SHOW CREATE VIEW v1;
+View	Create View
+v1	CREATE ALGORITHM=TEMPTABLE DEFINER=`root`@`localhost` SQL SECURITY INVOKER VIEW `v1` AS select `t1`.`x` AS `x` from `t1`
+ALTER VIEW v1 AS SELECT x, y FROM t1;
+SHOW CREATE VIEW v1;
+View	Create View
+v1	CREATE ALGORITHM=TEMPTABLE DEFINER=`root`@`localhost` SQL SECURITY INVOKER VIEW `v1` AS select `t1`.`x` AS `x`,`t1`.`y` AS `y` from `t1`
+DROP VIEW v1;
+DROP TABLE t1;
 CREATE TABLE t1 (s1 char);
 INSERT INTO t1 VALUES ('Z');
 CREATE VIEW v1 AS SELECT s1 collate latin1_german1_ci AS col FROM t1;
@@ -2820,3 +2831,22 @@ b
 c
 DROP VIEW v1, v2;
 DROP TABLE t1;
+CREATE TABLE t1 (id INT);
+CREATE VIEW v1 AS SELECT id FROM t1;
+SHOW TABLES;
+Tables_in_test
+t1
+v1
+DROP VIEW v2,v1;
+ERROR 42S02: Unknown table 'v2'
+SHOW TABLES;
+Tables_in_test
+t1
+CREATE VIEW v1 AS SELECT id FROM t1;
+DROP VIEW t1,v1;
+ERROR HY000: 'test.t1' is not VIEW
+SHOW TABLES;
+Tables_in_test
+t1
+DROP TABLE t1;
+DROP VIEW IF EXISTS v1;
diff --git a/mysql-test/t/mysql_client.test b/mysql-test/t/mysql_client.test
index e4b6658b631..003a086212e 100644
--- a/mysql-test/t/mysql_client.test
+++ b/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
diff --git a/mysql-test/t/view.test b/mysql-test/t/view.test
index 2099e07fadd..ee37429d694 100644
--- a/mysql-test/t/view.test
+++ b/mysql-test/t/view.test
@@ -2674,6 +2674,17 @@ DROP VIEW v1;
 DROP TABLE t1;
 
 #
+#Bug #21080: ALTER VIEW makes user restate SQL SECURITY mode, and ALGORITHM
+#
+CREATE TABLE t1 (x INT, y INT);
+CREATE ALGORITHM=TEMPTABLE SQL SECURITY INVOKER VIEW v1 AS SELECT x FROM t1;
+SHOW CREATE VIEW v1;
+
+ALTER VIEW v1 AS SELECT x, y FROM t1;
+SHOW CREATE VIEW v1;
+
+DROP VIEW v1;
+DROP TABLE t1;
 # Bug #21086: server crashes when VIEW defined with a SELECT with COLLATE 
 # clause is called
 #
@@ -2691,3 +2702,24 @@ INSERT INTO v2 (col) VALUES ('c');
 SELECT s1 FROM t1;
 DROP VIEW v1, v2;
 DROP TABLE t1;
+
+#
+# Bug #11551: Asymmetric + undocumented behaviour of DROP VIEW and DROP TABLE
+#
+CREATE TABLE t1 (id INT);
+CREATE VIEW v1 AS SELECT id FROM t1;
+SHOW TABLES;
+
+--error 1051
+DROP VIEW v2,v1;
+SHOW TABLES;
+
+CREATE VIEW v1 AS SELECT id FROM t1;
+--error 1347
+DROP VIEW t1,v1;
+SHOW TABLES;
+
+DROP TABLE t1;
+--disable_warnings
+DROP VIEW IF EXISTS v1;
+--enable_warnings
diff --git a/sql/sql_lex.h b/sql/sql_lex.h
index f42f70d4397..55dc6cb55a4 100644
--- a/sql/sql_lex.h
+++ b/sql/sql_lex.h
@@ -1047,7 +1047,7 @@ typedef struct st_lex : public Query_tables_list
   /*
     view created to be run from definer (standard behaviour)
   */
-  bool create_view_suid;
+  uint8 create_view_suid;
   /* Characterstics of trigger being created */
   st_trg_chistics trg_chistics;
   /*
diff --git a/sql/sql_view.cc b/sql/sql_view.cc
index d24b247a22f..546d940e3a4 100644
--- a/sql/sql_view.cc
+++ b/sql/sql_view.cc
@@ -155,6 +155,54 @@ err:
   DBUG_RETURN(TRUE);
 }
 
+/*
+  Fill defined view parts
+
+  SYNOPSIS
+    fill_defined_view_parts()
+      thd                current thread.
+      view               view to operate on
+
+  DESCRIPTION
+    This function will initialize the parts of the view 
+    definition that are not specified in ALTER VIEW
+    to their values from CREATE VIEW.
+    The view must be opened to get its definition.
+    We use a copy of the view when opening because we want 
+    to preserve the original view instance.
+
+  RETURN VALUE
+    TRUE                 can't open table
+    FALSE                success
+*/
+static bool
+fill_defined_view_parts (THD *thd, TABLE_LIST *view)
+{
+  LEX *lex= thd->lex;
+  bool not_used;
+  TABLE_LIST decoy;
+
+  memcpy (&decoy, view, sizeof (TABLE_LIST));
+  if (!open_table(thd, &decoy, thd->mem_root, &not_used, 0) &&
+      !decoy.view)
+  {
+    return TRUE;
+  }
+  if (!lex->definer)
+  {
+    view->definer.host= decoy.definer.host;
+    view->definer.user= decoy.definer.user;
+    lex->definer= &view->definer;
+  }
+  if (lex->create_view_algorithm == VIEW_ALGORITHM_UNDEFINED)
+    lex->create_view_algorithm= decoy.algorithm;
+  if (lex->create_view_suid == VIEW_SUID_DEFAULT)
+    lex->create_view_suid= decoy.view_suid ? 
+      VIEW_SUID_DEFINER : VIEW_SUID_INVOKER;
+
+  return FALSE;
+}
+
 
 /*
   Creating/altering VIEW procedure
@@ -207,7 +255,15 @@ bool mysql_create_view(THD *thd,
   }
 
   if (mode != VIEW_CREATE_NEW)
+  {
+    if (mode == VIEW_ALTER &&
+        fill_defined_view_parts(thd, view))
+    {
+      res= TRUE;
+      goto err;
+    }
     sp_cache_invalidate();
+  }
 
   if (!lex->definer)
   {
@@ -1238,6 +1294,10 @@ bool mysql_drop_view(THD *thd, TABLE_LIST *views, enum_drop_mode drop_mode)
 {
   char path[FN_REFLEN];
   TABLE_LIST *view;
+  frm_type_enum type;
+  String non_existant_views;
+  char *wrong_object_db= NULL, *wrong_object_name= NULL;
+  bool error= FALSE;
   enum legacy_db_type not_used;
   DBUG_ENTER("mysql_drop_view");
 
@@ -1248,8 +1308,9 @@ bool mysql_drop_view(THD *thd, TABLE_LIST *views, enum_drop_mode drop_mode)
     build_table_filename(path, sizeof(path),
                          view->db, view->table_name, reg_ext);
     VOID(pthread_mutex_lock(&LOCK_open));
-    if (access(path, F_OK) ||
-	(type= (mysql_frm_type(thd, path, &not_used) != FRMTYPE_VIEW)))
+    type= FRMTYPE_ERROR;
+    if (access(path, F_OK) || 
+        FRMTYPE_VIEW != (type= mysql_frm_type(thd, path, &not_used)))
     {
       char name[FN_REFLEN];
       my_snprintf(name, sizeof(name), "%s.%s", view->db, view->table_name);
@@ -1261,14 +1322,25 @@ bool mysql_drop_view(THD *thd, TABLE_LIST *views, enum_drop_mode drop_mode)
 	VOID(pthread_mutex_unlock(&LOCK_open));
 	continue;
       }
-      if (type)
-        my_error(ER_WRONG_OBJECT, MYF(0), view->db, view->table_name, "VIEW");
+      if (type == FRMTYPE_TABLE)
+      {
+        if (!wrong_object_name)
+        {
+          wrong_object_db= view->db;
+          wrong_object_name= view->table_name;
+        }
+      }
       else
-        my_error(ER_BAD_TABLE_ERROR, MYF(0), name);
-      goto err;
+      {
+        if (non_existant_views.length())
+          non_existant_views.append(',');
+        non_existant_views.append(String(view->table_name,system_charset_info));
+      }
+      VOID(pthread_mutex_unlock(&LOCK_open));
+      continue;
     }
     if (my_delete(path, MYF(MY_WME)))
-      goto err;
+      error= TRUE;
 
     /*
       For a view, there is only one table_share object which should never
@@ -1287,13 +1359,23 @@ bool mysql_drop_view(THD *thd, TABLE_LIST *views, enum_drop_mode drop_mode)
     sp_cache_invalidate();
     VOID(pthread_mutex_unlock(&LOCK_open));
   }
+  if (error)
+  {
+    DBUG_RETURN(TRUE);
+  }
+  if (wrong_object_name)
+  {
+    my_error(ER_WRONG_OBJECT, MYF(0), wrong_object_db, wrong_object_name, 
+             "VIEW");
+    DBUG_RETURN(TRUE);
+  }
+  if (non_existant_views.length())
+  {
+    my_error(ER_BAD_TABLE_ERROR, MYF(0), non_existant_views.c_ptr());
+    DBUG_RETURN(TRUE);
+  }
   send_ok(thd);
   DBUG_RETURN(FALSE);
-
-err:
-  VOID(pthread_mutex_unlock(&LOCK_open));
-  DBUG_RETURN(TRUE);
-
 }
 
 
diff --git a/sql/sql_yacc.yy b/sql/sql_yacc.yy
index 9236820cd25..b8d68a91afc 100644
--- a/sql/sql_yacc.yy
+++ b/sql/sql_yacc.yy
@@ -10866,11 +10866,11 @@ view_algorithm_opt:
 
 view_suid:
 	/* empty */
-	{ Lex->create_view_suid= TRUE; }
+	{ Lex->create_view_suid= VIEW_SUID_DEFAULT; }
 	| SQL_SYM SECURITY_SYM DEFINER_SYM
-	{ Lex->create_view_suid= TRUE; }
+	{ Lex->create_view_suid= VIEW_SUID_DEFINER; }
 	| SQL_SYM SECURITY_SYM INVOKER_SYM
-	{ Lex->create_view_suid= FALSE; }
+	{ Lex->create_view_suid= VIEW_SUID_INVOKER; }
 	;
 
 view_tail:
diff --git a/sql/table.h b/sql/table.h
index ee8dd7ac65e..0d8ec4f98e1 100644
--- a/sql/table.h
+++ b/sql/table.h
@@ -472,6 +472,10 @@ typedef struct st_schema_table
 #define VIEW_ALGORITHM_TMPTABLE         1
 #define VIEW_ALGORITHM_MERGE            2
 
+#define VIEW_SUID_INVOKER               0
+#define VIEW_SUID_DEFINER               1
+#define VIEW_SUID_DEFAULT               2
+
 /* view WITH CHECK OPTION parameter options */
 #define VIEW_CHECK_NONE       0
 #define VIEW_CHECK_LOCAL      1