Cache management is none of ArticleController business

src/ArticleController.h

@@ -76,7 +76,6 @@
 -(void)ensureSelectedArticle:(BOOL)singleSelection;
 -(void)sortByIdentifier:(NSString *)columnName;
 -(void)sortAscending:(BOOL)newAscending;
--(BOOL)currentCacheContainsFolder:(int)folderId;
 -(void)deleteArticlesByArray:(NSArray *)articleArray;
 -(void)markReadByArray:(NSArray *)articleArray readFlag:(BOOL)readFlag;
 -(void)markAllReadByReferencesArray:(NSArray *)refArray readFlag:(BOOL)readFlag;

src/ArticleController.m

@@ -314,7 +314,6 @@ -(void)displayFolder:(int)newFolderId
 {
 	if (currentFolderId != newFolderId && newFolderId != 0)
 	{
-		[[[Database sharedManager] folderFromID:currentFolderId] clearCache];
 		currentFolderId = newFolderId;
 		[self reloadArrayOfArticles];
 		[self sortArticles];
@@ -374,8 +373,6 @@ -(NSArray *)applyFilter:(NSArray *)unfilteredArray
 		Folder * folder = [[Database sharedManager] folderFromID:folderIdOfArticleToPreserve];
 		if (folder != nil)
 		{
-			[folder clearCache];
-			[folder articles];
 			articleToAdd = [folder articleFromGuid:guidOfArticleToPreserve];
 		}
 		if (articleToAdd == nil)
@@ -733,25 +730,6 @@ -(NSArray *)wrappedMarkAllReadInArray:(NSArray *)folderArray withUndo:(BOOL)undo
 	return refArray;
 }
 
-/* currentCacheContainsFolder
- * Scans the current article cache to determine if any article is a member of the specified
- * folder and returns YES if so.
- */
--(BOOL)currentCacheContainsFolder:(int)folderId
-{
-	int count = [currentArrayOfArticles count];
-	int index = 0;
-
-	while (index < count)
-	{
-		Article * anArticle = [currentArrayOfArticles objectAtIndex:index];
-		if ([anArticle folderId] == folderId)
-			return YES;
-		++index;
-	}
-	return NO;
-}
-
 /* markAllReadByReferencesArray
  * Given an array of references, mark all those articles read or unread.
  */

src/Folder.m

@@ -492,7 +492,8 @@ -(unsigned)indexOfArticle:(Article *)article
  */
 -(Article *)articleFromGuid:(NSString *)guid
 {
-	NSAssert(isCached, @"Folder's cache of articles should be initialized before articleFromGuid can be used");
+	if (!isCached)
+		[[Database sharedManager] arrayOfArticles:itemId filterString:nil];
 	return [cachedArticles objectForKey:guid];
 }