app_server: font style 0 may not exist

In which case failure to find it in the styles hash table does not tell
us anything about the existence of its family.

Change-Id: I77c8960a96e7283547650daae67ea71fd022567e
Reviewed-on: https://review.haiku-os.org/c/haiku/+/7631
Haiku-Format: Haiku-format Bot <[email protected]>
Reviewed-by: Fredrik Holmqvist <[email protected]>
Tested-by: Commit checker robot <[email protected]>
Reviewed-by: Adrien Destugues <[email protected]>

src/servers/app/font/FontManager.cpp

@@ -166,7 +166,8 @@ FontManager::GetFamily(uint16 familyID) const
 	if (style != NULL)
 		return style->Family();
 
-	return NULL;
+	// Try the slow route in case style 0 was removed
+	return _FindFamily(familyID);
 }
 
 
@@ -374,6 +375,21 @@ FontManager::_FindFamily(const char* name) const
 }
 
 
+FontFamily*
+FontManager::_FindFamily(uint16 familyID) const
+{
+	int32 count = fFamilies.CountItems();
+
+	for (int32 i = 0; i < count; i++) {
+		FontFamily* family = fFamilies.ItemAt(i);
+		if (family->ID() == familyID)
+			return family;
+	}
+
+	return NULL;
+}
+
+
 uint16
 FontManager::_NextID()
 {

src/servers/app/font/FontManager.h

@@ -67,6 +67,7 @@ protected:
 			FT_CharMap			_GetSupportedCharmap(const FT_Face& face);
 
 			FontFamily*			_FindFamily(const char* family) const;
+			FontFamily*			_FindFamily(uint16 familyID) const;
 
 			status_t			_AddFont(FT_Face face, node_ref nodeRef,
 									const char* path,

src/servers/app/font/GlyphLayoutEngine.h

@@ -429,20 +429,27 @@ GlyphLayoutEngine::PopulateFallbacks(
 		return;
 
 	static const int nFallbacks = B_COUNT_OF(fallbacks);
+	static const int acceptAnyStyle = 2;
 
-	for (int c = 0; c < 3; c++) {
+	for (int degradeLevel = 0; degradeLevel <= acceptAnyStyle; degradeLevel++) {
 		const char* fontStyle;
-		if (c == 0)
+		if (degradeLevel == 0)
 			fontStyle = font.Style();
-		else if (c == 1)
+		else if (degradeLevel == 1)
 			fontStyle = "Regular";
 		else
 			fontStyle = NULL;
 
 		for (int i = 0; i < nFallbacks; i++) {
 
-			FontStyle* fallbackStyle = gFontManager->GetStyle(fallbacks[i],
-				fontStyle, 0xffff, 0);
+			FontStyle* fallbackStyle;
+			if (degradeLevel != acceptAnyStyle) {
+				fallbackStyle = gFontManager->GetStyle(fallbacks[i], fontStyle);
+			} else {
+				// At this point we'll just take whatever we are given
+				fallbackStyle = gFontManager->GetStyleByIndex(fallbacks[i], 0);
+			}
+
 			if (fallbackStyle == NULL)
 				continue;
 
@@ -458,9 +465,7 @@ GlyphLayoutEngine::PopulateFallbacks(
 				fallbacksList.AddItem(cacheReference);
 			} else
 				FontCache::Default()->Recycle(entry);
-
 		}
-
 	}
 
 	gFontManager->Unlock();