From 4b34602eec3ebd70b83c4873076c23690f10af9a Mon Sep 17 00:00:00 2001
From: Dav999-v <dav999.tolp@gmail.com>
Date: Thu, 2 Feb 2023 23:22:24 +0100
Subject: [PATCH] Improve ordering of font charset loading

Even though it would be a bizarre combination, declaring no character
set (neither via <chars> nor via font.txt) meant that <special>
couldn't be used because the ASCII fallback charset would be loaded
after special ranges were processed. Now, all the methods of loading
the charset are attempted sequentially, and only afterwards, the
special ranges are loaded.
---
 desktop_version/src/Font.cpp | 114 +++++++++++++++++------------------
 1 file changed, 56 insertions(+), 58 deletions(-)

diff --git a/desktop_version/src/Font.cpp b/desktop_version/src/Font.cpp
index 54b15def..00bce86c 100644
--- a/desktop_version/src/Font.cpp
+++ b/desktop_version/src/Font.cpp
@@ -281,7 +281,7 @@ static uint8_t load_font(FontContainer* container, const char* name)
     }
     if (charmap != NULL)
     {
-        charset_loaded = true;
+        // We have a .txt! It's an obsolete system, but it takes priority if the file exists.
         unsigned char* current = charmap;
         unsigned char* end = charmap + length;
         int pos = 0;
@@ -293,73 +293,31 @@ static uint8_t load_font(FontContainer* container, const char* name)
         }
 
         VVV_free(charmap);
+        charset_loaded = true;
     }
 
-    if (xml_loaded)
+    if (xml_loaded && !charset_loaded && (pElem = hDoc.FirstChildElement("chars").ToElement()) != NULL)
     {
-        if (!charset_loaded && (pElem = hDoc.FirstChildElement("chars").ToElement()) != NULL)
+        // <chars> in the XML is the preferred system.
+        int pos = 0;
+        tinyxml2::XMLElement* subElem;
+        FOR_EACH_XML_SUB_ELEMENT(pElem, subElem)
         {
-            // <chars> in the XML is only looked at if we haven't already seen font.txt.
-            int pos = 0;
-            tinyxml2::XMLElement* subElem;
-            FOR_EACH_XML_SUB_ELEMENT(pElem, subElem)
+            EXPECT_ELEM(subElem, "range");
+
+            unsigned start, end;
+            if (!decode_xml_range(subElem, &start, &end))
             {
-                EXPECT_ELEM(subElem, "range");
-
-                unsigned start, end;
-                if (!decode_xml_range(subElem, &start, &end))
-                {
-                    continue;
-                }
-
-                for (uint32_t codepoint = start; codepoint <= end; codepoint++)
-                {
-                    add_glyphinfo(f, codepoint, pos);
-                    ++pos;
-                }
+                continue;
             }
-            charset_loaded = true;
-        }
 
-        if ((pElem = hDoc.FirstChildElement("special").ToElement()) != NULL)
-        {
-            tinyxml2::XMLElement* subElem;
-            FOR_EACH_XML_SUB_ELEMENT(pElem, subElem)
+            for (uint32_t codepoint = start; codepoint <= end; codepoint++)
             {
-                EXPECT_ELEM(subElem, "range");
-
-                unsigned start, end;
-                if (!decode_xml_range(subElem, &start, &end))
-                {
-                    continue;
-                }
-
-                int advance = subElem->IntAttribute("advance", -1);
-                int color = subElem->IntAttribute("color", -1);
-
-                for (uint32_t codepoint = start; codepoint <= end; codepoint++)
-                {
-                    GlyphInfo* glyph = get_glyphinfo(f, codepoint);
-                    if (glyph == NULL)
-                    {
-                        continue;
-                    }
-                    if (advance >= 0 && advance < 256)
-                    {
-                        glyph->advance = advance;
-                    }
-                    if (color == 0)
-                    {
-                        glyph->flags &= ~GLYPH_COLOR;
-                    }
-                    else if (color == 1)
-                    {
-                        glyph->flags |= GLYPH_COLOR;
-                    }
-                }
+                add_glyphinfo(f, codepoint, pos);
+                ++pos;
             }
-            special_loaded = true;
         }
+        charset_loaded = true;
     }
 
     if (!charset_loaded)
@@ -372,6 +330,46 @@ static uint8_t load_font(FontContainer* container, const char* name)
         }
     }
 
+    if (xml_loaded && (pElem = hDoc.FirstChildElement("special").ToElement()) != NULL)
+    {
+        tinyxml2::XMLElement* subElem;
+        FOR_EACH_XML_SUB_ELEMENT(pElem, subElem)
+        {
+            EXPECT_ELEM(subElem, "range");
+
+            unsigned start, end;
+            if (!decode_xml_range(subElem, &start, &end))
+            {
+                continue;
+            }
+
+            int advance = subElem->IntAttribute("advance", -1);
+            int color = subElem->IntAttribute("color", -1);
+
+            for (uint32_t codepoint = start; codepoint <= end; codepoint++)
+            {
+                GlyphInfo* glyph = get_glyphinfo(f, codepoint);
+                if (glyph == NULL)
+                {
+                    continue;
+                }
+                if (advance >= 0 && advance < 256)
+                {
+                    glyph->advance = advance;
+                }
+                if (color == 0)
+                {
+                    glyph->flags &= ~GLYPH_COLOR;
+                }
+                else if (color == 1)
+                {
+                    glyph->flags |= GLYPH_COLOR;
+                }
+            }
+        }
+        special_loaded = true;
+    }
+
     if (!special_loaded && f->glyph_w == 8 && f->glyph_h == 8)
     {
         /* If we don't have <special>, and the font is 8x8,