embed the standard scaling rules

packaging/macos/bundle.py

@@ -12,6 +12,7 @@ import re
 import shutil
 import subprocess
 import sys
+import xml.etree.ElementTree as ET
 
 ROOT = Path(__file__).resolve().parents[2]
 MACH_MAGIC = {bytes.fromhex(h) for h in ("feedface", "cefaedfe", "feedfacf", "cffaedfe", "cafebabe", "bebafeca", "cafebabf", "bfbafeca")}
@@ -123,6 +124,29 @@ def copy_tree(source: Path, target: Path) -> None:
         shutil.copytree(source, target, dirs_exist_ok=True, symlinks=False)
 
 
+def write_fontconfig(resources: Path, fontconfig_prefix: Path) -> None:
+    # Noto Color Emoji has fixed-size color bitmaps. Fontconfig supplies the
+    # requested-size/strike-size matrix; without it glyphs render at 109px.
+    rule = fontconfig_prefix / "share/fontconfig/conf.avail/10-scale-bitmap-fonts.conf"
+    if not rule.is_file():
+        raise RuntimeError(f"Required Fontconfig bitmap scaling rules not found: {rule}")
+    resources.mkdir(parents=True, exist_ok=True)
+    config = ET.fromstring('''<fontconfig>
+  <dir>/System/Library/Fonts</dir><dir>/Library/Fonts</dir><dir>~/Library/Fonts</dir>
+  <cachedir prefix="xdg">fontconfig</cachedir>
+  <alias><family>sans-serif</family><prefer><family>Helvetica</family></prefer></alias>
+  <alias><family>monospace</family><prefer><family>Menlo</family></prefer></alias>
+</fontconfig>
+''')
+    # Embed the standard rules so they work after relocation without depending
+    # on Homebrew or Fontconfig's host configuration search paths.
+    for element in reversed(list(ET.parse(rule).getroot())):
+        config.insert(0, element)
+    (resources / "fonts.conf").write_text(
+        '<?xml version="1.0"?>\n<!DOCTYPE fontconfig SYSTEM "urn:fontconfig:fonts.dtd">\n' +
+        ET.tostring(config, encoding="unicode") + "\n", encoding="utf-8")
+
+
 def audit(app: Path) -> dict[str, object]:
     binary = app / "Contents/MacOS/zoitechat"
     architectures = set(run("lipo", "-archs", binary).split())
@@ -180,7 +204,7 @@ def package(stage: Path, app: Path, build_number: str) -> None:
             seeds.append((source, resources / "lib/zoitechat/plugins" / source.name))
 
     prefixes = {formula: Path(run("brew", "--prefix", formula)) for formula in (
-        "gtk+3", "gdk-pixbuf", "glib", "glib-networking", "librsvg", "enchant", "adwaita-icon-theme", "hicolor-icon-theme", "gsettings-desktop-schemas", "ca-certificates", "openssl@3", "lua", "libarchive", "gtk-mac-integration")}
+        "gtk+3", "gdk-pixbuf", "glib", "glib-networking", "librsvg", "enchant", "adwaita-icon-theme", "hicolor-icon-theme", "gsettings-desktop-schemas", "ca-certificates", "openssl@3", "lua", "libarchive", "gtk-mac-integration", "fontconfig")}
     # Runtime-loaded code is not visible in the main executable's otool output.
     module_groups = [
         (prefixes["gdk-pixbuf"] / "lib/gdk-pixbuf-2.0/2.10.0/loaders", "lib/gdk-pixbuf-2.0/2.10.0/loaders"),
@@ -241,15 +265,7 @@ def package(stage: Path, app: Path, build_number: str) -> None:
             data = data.replace(str(source), "@ZOITECHAT_RESOURCES@/" + str(target.relative_to(resources)))
         (resources / cache).write_text(data + "\n")
     # The private font map loads the bundled Noto font; ordinary GTK fonts stay local.
-    (resources / "fonts.conf").write_text('''<?xml version="1.0"?>
-<!DOCTYPE fontconfig SYSTEM "urn:fontconfig:fonts.dtd">
-<fontconfig>
-  <dir>/System/Library/Fonts</dir><dir>/Library/Fonts</dir><dir>~/Library/Fonts</dir>
-  <cachedir prefix="xdg">fontconfig</cachedir>
-  <alias><family>sans-serif</family><prefer><family>Helvetica</family></prefer></alias>
-  <alias><family>monospace</family><prefer><family>Menlo</family></prefer></alias>
-</fontconfig>
-''')
+    write_fontconfig(resources, prefixes["fontconfig"])
     (resources / "zoitechat-bundle").write_text("1\n")
     licenses = resources / "licenses"
     licenses.mkdir()

packaging/macos/tests/test_bundle.py

@@ -1,16 +1,63 @@
 """Dependency parsing, relocation guards and release audit tests without a Mac SDK."""
 from pathlib import Path
+import os
 import shutil
+import subprocess
 import sys
 import tempfile
 import unittest
 from unittest.mock import patch
+from xml.sax.saxutils import escape
 
 sys.path.insert(0, str(Path(__file__).resolve().parents[1]))
 import bundle
 
 
 class BundleTests(unittest.TestCase):
+    def test_missing_bitmap_scaling_rules_fail_packaging(self):
+        with tempfile.TemporaryDirectory() as temporary:
+            directory = Path(temporary)
+            with self.assertRaisesRegex(RuntimeError, "bitmap scaling rules not found"):
+                bundle.write_fontconfig(directory / "Resources", directory / "missing-prefix")
+
+    @unittest.skipUnless(shutil.which("fc-match"), "requires Fontconfig's matching tool")
+    def test_bundled_bitmap_scaling_survives_relocation(self):
+        prefix = Path(bundle.run("brew", "--prefix", "fontconfig")) if sys.platform == "darwin" else Path("/usr")
+        rule = prefix / "share/fontconfig/conf.avail/10-scale-bitmap-fonts.conf"
+        if not rule.is_file():
+            self.skipTest("Fontconfig bitmap scaling configuration unavailable")
+        font = bundle.ROOT / "data/fonts/NotoColorEmoji.ttf"
+        with tempfile.TemporaryDirectory(prefix="zoitechat font scaling ") as temporary:
+            directory = Path(temporary)
+            source = directory / "build-prefix/share/fontconfig/conf.avail" / rule.name
+            source.parent.mkdir(parents=True)
+            shutil.copy2(rule, source)
+            resources = directory / "Resources"
+            bundle.write_fontconfig(resources, directory / "build-prefix")
+            relocated = directory / "Relocated Resources"
+            shutil.move(resources, relocated)
+            source.unlink()
+            # Exercise the shipped configuration without consulting host font
+            # rules. Only the bundled font is visible after reset-dirs.
+            wrapper = directory / "probe.conf"
+            wrapper.write_text(
+                '<fontconfig><include>' + escape(str(relocated / "fonts.conf")) +
+                '</include><reset-dirs/><dir>' + escape(str(font.parent)) + '</dir></fontconfig>')
+            env = os.environ.copy()
+            env["FONTCONFIG_FILE"] = str(wrapper)
+            env["XDG_CACHE_HOME"] = str(directory / "cache")
+            for requested in (12, 16, 24):
+                output = subprocess.check_output(
+                    ["fc-match", "-f", "%{pixelsize}\\n%{matrix}\\n%{file}\\n",
+                     f"Noto Color Emoji:pixelsize={requested}"], env=env, cwd=directory, text=True)
+                pixels, matrix, matched = output.splitlines()
+                self.assertEqual(Path(matched).resolve(), font.resolve())
+                values = [float(value) for value in matrix.split()]
+                self.assertEqual(len(values), 4, "bitmap scaling matrix missing")
+                self.assertAlmostEqual(float(pixels) * values[0], requested, places=3)
+                self.assertAlmostEqual(float(pixels) * values[3], requested, places=3)
+                self.assertEqual(values[1:3], [0.0, 0.0])
+
     @unittest.skipUnless(sys.platform == "darwin", "requires Apple's Mach-O tools")
     def test_signed_binary_relocation_and_resigning(self):
         with tempfile.TemporaryDirectory(prefix="zoitechat relocation ") as temporary: