Fix for crash when attempting to print non-existant characters

git-svn-id: svn://svn.code.sf.net/p/sc2/code/trunk@1585 8092fc87-c524-0410-9efc-e669fe64eaf9

sc2/src/sc2code/libs/graphics/font.c

@@ -327,8 +327,10 @@ _text_blt (PRECT pClipRect, PRIMITIVEPTR PrimPtr)
 }
 
 static inline FRAME_DESC *
-getCharFrame (FONT_DESC *fontPtr, wchar_t ch) {
+getCharFrame (FONT_DESC *fontPtr, wchar_t ch)
+{
 	wchar_t pageStart = ch & CHARACTER_PAGE_MASK;
+	size_t charIndex;
 
 	FONT_PAGE *page = fontPtr->fontPages;
 	for (;;)
@@ -342,6 +344,18 @@ getCharFrame (FONT_DESC *fontPtr, wchar_t ch) {
 		page = page->next;
 	}
 
-	return &page->charDesc[ch - page->firstChar];
+	charIndex = ch - page->firstChar;
+	if (ch >= page->firstChar && charIndex < page->numChars
+			&& page->charDesc[charIndex].image)
+	{
+		return &page->charDesc[charIndex];
+	}
+	else
+	{
+#ifdef DEBUG
+		fprintf (stderr, "Character %u not present\n");
+#endif
+		return NULL;
+	}
 }