Fix #238 Error on importing sub-forum before its parent's been merged. And code improvement. (#239)

* Fix mybb/merge-system:#238 SMF2 module's error on processing sub-forum before its parent's been merged.

* Fix mybb/merge-system:#238 SMF module's error on importing sub-forum before its parent's been merged.
Improve code format for SMF2's forum module.

* Add a TODO mark to lines relating to mybb/merge-system:#238.

* Improve code quality: remove some redundant code in `import_forums` module of vbulletin3/vbulletin4/vbulletin5.

* Code improvement.

* Revert "Add a TODO mark to lines relating to mybb/merge-system:#238."

This reverts commit eb09a98.

* Add default value (integer) for field `pid` in forums base module

Author: yuliu

boards/smf/forums.php

@@ -43,10 +43,17 @@ function convert_data($data)
 
 		if($data['ID_PARENT'])
 		{
-			$insert_data['pid'] = $this->get_import->fid_f($data['ID_PARENT']);
+			// Parent forum is a board.
+			$insert_data['import_pid'] = $data['ID_PARENT'];
+
+			// Assign the already merged parent board's ID, otherwise 0.
+			$pid = $this->get_import->fid_f($data['ID_PARENT']);
+			$insert_data['pid'] = empty($pid) ? 0 : $pid;
 		}
 		else
 		{
+			// Parent forum is a category. All categories should have been already merged.
+			$insert_data['import_pid'] = $data['ID_CAT'];	// TODO: may needn't this, and this could be confusing.
 			$insert_data['pid'] = $this->get_import->fid_c($data['ID_CAT']);
 		}
 
@@ -71,6 +78,26 @@ function fetch_total()
 		return $import_session['total_forums'];
 	}
 
+	/**
+	 * Update imported forums that don't have a parent forum assigned.
+	 */
+	function finish()
+	{
+		global $db;
+
+		// 'f' type forum. Column `pid`'s value is 0 if this forum is merged before its parent being merged.
+		$query = $db->simple_select("forums", "fid,import_pid", "type = 'f' AND import_fid != 0 AND pid = 0");
+		while($forum = $db->fetch_array($query))
+		{
+			$pid = $this->get_import->fid($forum['import_pid']);
+			if(!empty($pid))	// Do another check, failure will leave dirty work to parent class's cleanup() function.
+			{
+				$db->update_query("forums", array('pid' => $pid), "fid='{$forum['fid']}'", 1);
+			}
+		}
+		$db->free_result($query);
+	}
+
 	/**
 	 * Correctly associate any forums with their correct parent ids. This is automagically run after importing
 	 * forums.

boards/smf2/forums.php

@@ -43,10 +43,17 @@ function convert_data($data)
 
 		if($data['id_parent'])
 		{
-			$insert_data['pid'] = $this->get_import->fid_f($data['id_parent']);
+			// Parent forum is a board.
+			$insert_data['import_pid'] = $data['id_parent'];
+
+			// Assign the already merged parent board's ID, otherwise 0.
+			$pid = $this->get_import->fid_f($data['id_parent']);
+			$insert_data['pid'] = empty($pid) ? 0 : $pid;
 		}
 		else
 		{
+			// Parent forum is a category. All categories should have been already merged.
+			$insert_data['import_pid'] = $data['id_cat'];	// TODO: may needn't this, and this could be confusing.
 			$insert_data['pid'] = $this->get_import->fid_c($data['id_cat']);
 		}
 
@@ -71,6 +78,26 @@ function fetch_total()
 		return $import_session['total_forums'];
 	}
 
+	/**
+	 * Update imported forums that don't have a parent forum assigned.
+	 */
+	function finish()
+	{
+		global $db;
+
+		// 'f' type forum. Column `pid`'s value is 0 if this forum is merged before its parent being merged.
+		$query = $db->simple_select("forums", "fid,import_pid", "type = 'f' AND import_fid != 0 AND pid = 0");
+		while($forum = $db->fetch_array($query))
+		{
+			$pid = $this->get_import->fid($forum['import_pid']);
+			if(!empty($pid))	// Do another check, failure will leave dirty work to parent class's cleanup() function.
+			{
+				$db->update_query("forums", array('pid' => $pid), "fid='{$forum['fid']}'", 1);
+			}
+		}
+		$db->free_result($query);
+	}
+
 	/**
 	 * Correctly associate any forums with their correct parent ids. This is automagically run after importing
 	 * forums.

boards/vbulletin3/forums.php

@@ -59,7 +59,6 @@ function convert_data($data)
 		if($data['parentid'] == '-1')
 		{
 			$insert_data['type'] = 'c';
-			$insert_data['import_fid'] = $data['forumid'];
 		}
 		// We have a forum
 		else

boards/vbulletin4/forums.php

@@ -59,7 +59,6 @@ function convert_data($data)
 		if($data['parentid'] == '-1')
 		{
 			$insert_data['type'] = 'c';
-			$insert_data['import_fid'] = $data['forumid'];
 		}
 		// We have a forum
 		else

boards/vbulletin5/forums.php

@@ -59,7 +59,6 @@ function convert_data($data)
 		if($data['parentid'] == '-1')
 		{
 			$insert_data['type'] = 'c';
-			$insert_data['import_fid'] = $data['forumid'];
 		}
 		// We have a forum
 		else

resources/modules/forums.php

@@ -25,6 +25,7 @@ abstract class Converter_Module_Forums extends Converter_Module
 		'threads' => 0,
 		'posts' => 0,
 		'type' => 'f',
+		'pid' => 0,
 		'active' => 1,
 		'open' => 1,
 		'allowhtml' => 0,
@@ -58,6 +59,7 @@ abstract class Converter_Module_Forums extends Converter_Module
 		'lastposteruid',
 		'threads',
 		'posts',
+		'pid',
 		'active',
 		'open',
 		'allowhtml',