BUG#26881798: SERVER EXITS WHEN PRIMARY KEY IN MYSQL.PROC

              IS DROPPED

ANALYSIS:
=========
It is advised not to tamper with the system tables.
When primary key is dropped from a system table, certain
operations on the table which tries to access the table key
information may lead to server exit.

FIX:
====
An appropriate error is now reported in such a case.

sql/event_db_repository.cc

@@ -1,5 +1,5 @@
 /*
-   Copyright (c) 2006, 2011, Oracle and/or its affiliates. All rights reserved.
+   Copyright (c) 2006, 2017, Oracle and/or its affiliates. All rights reserved.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -174,6 +174,8 @@ class Event_db_intact : public Table_check_intact
     error_log_print(ERROR_LEVEL, fmt, args);
     va_end(args);
   }
+public:
+  Event_db_intact() { has_keys= TRUE; }
 };
 
 /** In case of an error, a message is printed to the error log. */

sql/sp.cc

@@ -1,5 +1,5 @@
 /*
-   Copyright (c) 2002, 2016, Oracle and/or its affiliates. All rights reserved.
+   Copyright (c) 2002, 2017, Oracle and/or its affiliates. All rights reserved.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -351,7 +351,7 @@ class Proc_table_intact : public Table_check_intact
   bool m_print_once;
 
 public:
-  Proc_table_intact() : m_print_once(TRUE) {}
+  Proc_table_intact() : m_print_once(TRUE) { has_keys= TRUE; }
 
 protected:
   void report_error(uint code, const char *fmt, ...);

sql/sql_acl.cc

@@ -1,4 +1,4 @@
-/* Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.
+/* Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -949,6 +949,8 @@ class Acl_table_intact : public Table_check_intact
       va_end(args);
     }
   }
+public:
+  Acl_table_intact() { has_keys= TRUE; }
 };
 
 #define IP_ADDR_STRLEN (3 + 1 + 3 + 1 + 3 + 1 + 3)

sql/sql_plugin.cc

@@ -1,5 +1,5 @@
 /*
-   Copyright (c) 2005, 2013, Oracle and/or its affiliates. All rights reserved.
+   Copyright (c) 2005, 2017, Oracle and/or its affiliates. All rights reserved.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -1899,6 +1899,16 @@ bool mysql_uninstall_plugin(THD *thd, const LEX_STRING *name)
   if (! (table= open_ltable(thd, &tables, TL_WRITE, MYSQL_LOCK_IGNORE_TIMEOUT)))
     DBUG_RETURN(TRUE);
 
+  if (!table->key_info)
+  {
+    my_printf_error(ER_UNKNOWN_ERROR,
+                    "The table '%s.%s' does not have the necessary key(s) "
+                    "defined on it. Please check the table definition and "
+                    "create index(s) accordingly.", MYF(0),
+                    table->s->db.str, table->s->table_name.str);
+    DBUG_RETURN(TRUE);
+  }
+
   /*
     Pre-acquire audit plugins for events that may potentially occur
     during [UN]INSTALL PLUGIN.

sql/table.cc

@@ -1,5 +1,5 @@
 /*
-   Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.
+   Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -3013,7 +3013,7 @@ Table_check_intact::check(TABLE *table, const TABLE_FIELD_DEF *table_def)
 
   /* Whether the table definition has already been validated. */
   if (table->s->table_field_def_cache == table_def)
-    DBUG_RETURN(FALSE);
+    goto end;
 
   if (table->s->fields != table_def->count)
   {
@@ -3129,6 +3129,18 @@ Table_check_intact::check(TABLE *table, const TABLE_FIELD_DEF *table_def)
   if (! error)
     table->s->table_field_def_cache= table_def;
 
+end:
+
+  if (has_keys && !error && !table->key_info)
+  {
+    my_printf_error(ER_UNKNOWN_ERROR,
+                    "The table '%s.%s' does not have the necessary key(s) "
+                    "defined on it. Please check the table definition and "
+                    "create index(s) accordingly.", MYF(0),
+                    table->s->db.str, table->s->table_name.str);
+    error= TRUE;
+  }
+
   DBUG_RETURN(error);
 }
 

sql/table.h

@@ -1,7 +1,7 @@
 #ifndef TABLE_INCLUDED
 #define TABLE_INCLUDED
 
-/* Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.
+/* Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -484,10 +484,11 @@ typedef struct st_ha_data_partition
 class Table_check_intact
 {
 protected:
+  bool has_keys;
   virtual void report_error(uint code, const char *fmt, ...)= 0;
 
 public:
-  Table_check_intact() {}
+  Table_check_intact() : has_keys(FALSE) {}
   virtual ~Table_check_intact() {}
 
   /** Checks whether a table is intact. */