Throw an error when during a restore operation the user tries to remap

an external directory that is not in the destination backup

src/dir.c

@@ -1263,8 +1263,47 @@ check_tablespace_mapping(pgBackup *backup)
 	parray_free(links);
 }
 
+void
+check_extra_dir_mapping(pgBackup *backup)
+{
+	TablespaceListCell *cell;
+	parray *extra_dirs_to_restore;
+	bool	found;
+	int		i;
+
+	if (!backup->extra_dir_str)
+	{
+	 	if (extra_remap_list.head)
+			elog(ERROR, "--extra-mapping option's old directory doesn't have "
+				 "an entry in list of extra directories of current "
+				 "backup: \"%s\"", extra_remap_list.head->old_dir);
+		return;
+	}
+	
+	extra_dirs_to_restore = make_extra_directory_list(backup->extra_dir_str);
+	for (cell = extra_remap_list.head; cell; cell = cell->next)
+	{
+		char *old_dir = cell->old_dir;
+
+		found = false;
+		for (i = 0; i < parray_num(extra_dirs_to_restore); i++)
+		{
+			char *external_dir = parray_get(extra_dirs_to_restore, i);
+			if (strcmp(old_dir, external_dir) == 0)
+			{
+				found = true;
+				break;
+			}
+		}
+		if (!found)
+			elog(ERROR, "--extra-mapping option's old directory doesn't have "
+				 "an entry in list of extra directories of current "
+				 "backup: \"%s\"", cell->old_dir);
+	}
+}
+
 char *
-check_extra_dir_mapping(char *current_dir)
+get_extra_remap(char *current_dir)
 {
 	TablespaceListCell *cell;
 

src/pg_probackup.h

@@ -509,7 +509,8 @@ extern void read_tablespace_map(parray *files, const char *backup_dir);
 extern void opt_tablespace_map(ConfigOption *opt, const char *arg);
 extern void opt_extradir_map(ConfigOption *opt, const char *arg);
 extern void check_tablespace_mapping(pgBackup *backup);
-extern char* check_extra_dir_mapping(char *current_dir);
+extern void check_extra_dir_mapping(pgBackup *backup);
+extern char *get_extra_remap(char *current_dir);
 
 extern void print_file_list(FILE *out, const parray *files, const char *root,
 							const char *extra_prefix, parray *extra_list);

src/restore.c

@@ -285,7 +285,10 @@ do_restore_or_validate(time_t target_backup_id, pgRecoveryTarget *rt,
 	 * i.e. empty or not exist.
 	 */
 	if (is_restore)
+	{
 		check_tablespace_mapping(dest_backup);
+		check_extra_dir_mapping(dest_backup);
+	}
 
 	if (!is_restore || !rt->restore_no_validate)
 	{
@@ -461,10 +464,10 @@ restore_backup(pgBackup *backup, const char *extra_dir_str)
 	if(extra_dir_str)
 	{
 		requested_extra_dirs = make_extra_directory_list(extra_dir_str);
-		for (int i = 0; i < parray_num(requested_extra_dirs); i++)
+		for (i = 0; i < parray_num(requested_extra_dirs); i++)
 		{
 			char *extra_path = parray_get(requested_extra_dirs, i);
-			extra_path = check_extra_dir_mapping(extra_path);
+			extra_path = get_extra_remap(extra_path);
 			dir_create_dir(extra_path, DIR_PERMISSION);
 		}
 	}
@@ -507,7 +510,7 @@ restore_backup(pgBackup *backup, const char *extra_dir_str)
 			{
 				char		container_dir[MAXPGPATH];
 
-				extra_path = check_extra_dir_mapping(extra_path);
+				extra_path = get_extra_remap(extra_path);
 				makeExtraDirPathByNum(container_dir, extra_prefix,
 									  file->extra_dir_num);
 				dir_name = GetRelativePath(file->path, container_dir);
@@ -698,7 +701,7 @@ restore_files(void *arg)
 												file->extra_dir_num - 1);
 			if (backup_contains_extra(extra_path, arguments->req_extra_dirs))
 			{
-				extra_path = check_extra_dir_mapping(extra_path);
+				extra_path = get_extra_remap(extra_path);
 				copy_file(arguments->extra_prefix, extra_path, file);
 			}
 		}

tests/external.py

@@ -127,8 +127,8 @@ class ExternalTest(ProbackupTest, unittest.TestCase):
                     repr(self.output), self.cmd))
         except ProbackupException as e:
             self.assertTrue(
-                'ERROR: --tablespace-mapping option' in e.message and
-                'have an entry in tablespace_map file' in e.message,
+                'ERROR: --extra-mapping option' in e.message and
+                'have an entry in list of extra directories' in e.message,
                 '\n Unexpected Error Message: {0}\n CMD: {1}'.format(
                     repr(e.message), self.cmd))