Bug#41190: shared memory connections do not work in Vista, if server started from cmdline

Backport to MySQL 5.0/1 fix by Vladislav Vaintroub:

In Vista and later and also in when using terminal services, when
server is started from  command line, client cannot connect to it
via shared memory protocol.

This is a regression introduced when  Bug#24731 was fixed.  The
reason is that client is trying to attach to shared memory using
global kernel object  namespace (all kernel objects are prefixed
with Global\). However, server started from the command line in
Vista and later will create shared memory and events using current
session namespace. Thus, client is unable to find the server and
connection fails.

The fix for the client is to first try to find server using "local"
names  (omitting Global\  prefix) and only if server is not found,
trying global namespace.

sql-common/client.c

@@ -412,6 +412,9 @@ HANDLE create_shared_memory(MYSQL *mysql,NET *net, uint connect_timeout)
   DWORD error_code = 0;
   DWORD event_access_rights= SYNCHRONIZE | EVENT_MODIFY_STATE;
   char *shared_memory_base_name = mysql->options.shared_memory_base_name;
+  static const char *name_prefixes[] = {"","Global\\"};
+  const char *prefix;
+  int i;
 
   /*
      get enough space base-name + '_' + longest suffix we might ever send
@@ -426,9 +429,18 @@ HANDLE create_shared_memory(MYSQL *mysql,NET *net, uint connect_timeout)
     shared_memory_base_name is unique value for each server
     unique_part is uniquel value for each object (events and file-mapping)
   */
-  suffix_pos = strxmov(tmp, "Global\\", shared_memory_base_name, "_", NullS);
-  strmov(suffix_pos, "CONNECT_REQUEST");
-  if (!(event_connect_request= OpenEvent(event_access_rights, FALSE, tmp)))
+  for (i = 0; i< array_elements(name_prefixes); i++)
+  {
+    prefix= name_prefixes[i];
+    suffix_pos = strxmov(tmp, prefix , shared_memory_base_name, "_", NullS);
+    strmov(suffix_pos, "CONNECT_REQUEST");
+    event_connect_request= OpenEvent(event_access_rights, FALSE, tmp);
+    if (event_connect_request)
+    {
+      break;
+    }
+  }
+  if (!event_connect_request)
   {
     error_allow = CR_SHARED_MEMORY_CONNECT_REQUEST_ERROR;
     goto err;
@@ -480,7 +492,7 @@ HANDLE create_shared_memory(MYSQL *mysql,NET *net, uint connect_timeout)
     unique_part is uniquel value for each object (events and file-mapping)
     number_of_connection is number of connection between server and client
   */
-  suffix_pos = strxmov(tmp, "Global\\", shared_memory_base_name, "_", connect_number_char,
+  suffix_pos = strxmov(tmp, prefix , shared_memory_base_name, "_", connect_number_char,
 		       "_", NullS);
   strmov(suffix_pos, "DATA");
   if ((handle_file_map = OpenFileMapping(FILE_MAP_WRITE,FALSE,tmp)) == NULL)