Add support for ttx(1) from fonttools. (Re: reproducible-builds/diffoscope#315)

debian/control

@@ -29,6 +29,7 @@ Build-Depends:
  ffmpeg <!nocheck>,
  flake8 <!nocheck>,
  fontforge-extras <!nocheck>,
+ fonttools <!nocheck>,
  fp-utils [!ppc64el !s390x] <!nocheck>,
  ghc <!nocheck>,
  ghostscript <!nocheck>,

debian/tests/control

@@ -7,7 +7,7 @@
 #   $ mv debian/tests/control.tmp debian/tests/control
 
 Tests: pytest-with-recommends
-Depends: python3-all, diffoscope, black, python3-pytest, python3-h5py, file, linux-image-amd64 [amd64] | linux-image-generic [amd64], abootimg, acl, apksigner, apktool [!ppc64el !s390x], binutils-multiarch, bzip2, caca-utils, colord, coreboot-utils, db-util, default-jdk-headless | default-jdk | java-sdk, device-tree-compiler, docx2txt, e2fsprogs, enjarify, ffmpeg, fontforge-extras, fp-utils [!ppc64el !s390x], genisoimage, gettext, ghc, ghostscript, giflib-tools, gnumeric, gnupg, gnupg-utils, hdf5-tools, imagemagick, jsbeautifier, libarchive-tools, libxmlb-dev, llvm, lz4 | liblz4-tool, mono-utils, ocaml-nox, odt2txt, oggvideotools [!s390x], openssh-client, openssl, pgpdump, poppler-utils, procyon-decompiler, python3-pdfminer, r-base-core, rpm2cpio, sng, sqlite3, squashfs-tools, tcpdump, u-boot-tools, unzip, wabt, xmlbeans, xxd, xz-utils, zip, zstd, androguard, python3-argcomplete, python3-binwalk, python3-defusedxml, python3-distro, python3-guestfs, python3-jsondiff, python3-progressbar, python3-pypdf2, python3-debian, python3-pyxattr, python3-rpm, python3-tlsh
+Depends: python3-all, diffoscope, black, python3-pytest, python3-h5py, file, linux-image-amd64 [amd64] | linux-image-generic [amd64], abootimg, acl, apksigner, apktool [!ppc64el !s390x], binutils-multiarch, bzip2, caca-utils, colord, coreboot-utils, db-util, default-jdk-headless | default-jdk | java-sdk, device-tree-compiler, docx2txt, e2fsprogs, enjarify, ffmpeg, fontforge-extras, fonttools, fp-utils [!ppc64el !s390x], genisoimage, gettext, ghc, ghostscript, giflib-tools, gnumeric, gnupg, gnupg-utils, hdf5-tools, imagemagick, jsbeautifier, libarchive-tools, libxmlb-dev, llvm, lz4 | liblz4-tool, mono-utils, ocaml-nox, odt2txt, oggvideotools [!s390x], openssh-client, openssl, pgpdump, poppler-utils, procyon-decompiler, python3-pdfminer, r-base-core, rpm2cpio, sng, sqlite3, squashfs-tools, tcpdump, u-boot-tools, unzip, wabt, xmlbeans, xxd, xz-utils, zip, zstd, 
 
 Tests: pytest
 Depends: python3-all, diffoscope, python3-pytest, python3-h5py, file, python3-tlsh

diffoscope/comparators/fonts.py

@@ -2,7 +2,7 @@
 # diffoscope: in-depth comparison of files, archives, and directories
 #
 # Copyright © 2014-2015 Jérémy Bobbio <lunar@debian.org>
-# Copyright © 2015-2018, 2020 Chris Lamb <lamby@debian.org>
+# Copyright © 2015-2018, 2020, 2022 Chris Lamb <lamby@debian.org>
 #
 # diffoscope is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -19,6 +19,7 @@
 
 import re
 
+from diffoscope.exc import RequiredToolNotFound
 from diffoscope.tools import tool_required
 from diffoscope.difference import Difference
 
@@ -35,9 +36,23 @@ class Showttf(Command):
         return line.decode("latin-1").encode("utf-8")
 
 
+class Ttx(Command):
+    @tool_required("ttx")
+    def cmdline(self):
+        return ["ttx", "-o-", self.path]
+
+
 class TtfFile(File):
     DESCRIPTION = "TrueType font files"
     FILE_TYPE_RE = re.compile(r"^(TrueType|OpenType) font data", re.IGNORECASE)
 
     def compare_details(self, other, source=None):
-        return [Difference.from_operation(Showttf, self.path, other.path)]
+        xs = []
+
+        for x in (Showttf, Ttx):
+            try:
+                xs.append(Difference.from_operation(x, self.path, other.path))
+            except RequiredToolNotFound as exc:
+                self.add_comment(exc.get_comment())
+
+        return xs

diffoscope/external_tools.py

@@ -216,6 +216,7 @@ EXTERNAL_TOOLS = {
     "wasm2wat": {"debian": "wabt", "arch": "wabt", "guix": "wabt"},
     "tar": {"debian": "tar", "arch": "tar", "guix": "tar"},
     "tcpdump": {"debian": "tcpdump", "arch": "tcpdump", "guix": "tcpdump"},
+    "ttx": {"debian": "fonttools"},
     "unsquashfs": {
         "debian": "squashfs-tools",
         "arch": "squashfs-tools",

tests/comparators/test_fonts.py

@@ -46,11 +46,14 @@ def differences(ttf1, ttf2):
 
 
 @skip_unless_tools_exist("showttf")
+@skip_unless_tools_exist("ttx")
 def test_diff(differences):
     assert_diff(differences[0], "ttf_expected_diff")
+    assert_diff(differences[1], "ttf_ttx_expected_diff")
 
 
 @skip_unless_tools_exist("showttf")
+@skip_unless_tools_exist("ttx")
 def test_compare_non_existing(monkeypatch, ttf1):
     monkeypatch.setattr(Config(), "new_file", True)
     difference = ttf1.compare(MissingFile("/nonexisting", ttf1))

tests/data/ttf_ttx_expected_diff

+@@ -216,15 +216,15 @@
+     <GlyphID id="210" name="uni0D41_uni0D4D"/>
+   </GlyphOrder>
+ 
+   <head>
+     <!-- Most of this table will be recalculated by the compiler -->
+     <tableVersion value="1.0"/>
+     <fontRevision value="1.2"/>
+-    <checkSumAdjustment value="0x2d668113"/>
++    <checkSumAdjustment value="0x2966810f"/>
+     <magicNumber value="0x5f0f3cf5"/>
+     <flags value="00000000 00011111"/>
+     <unitsPerEm value="1024"/>
+     <created value="Fri Jan  6 19:21:03 2006"/>
+     <modified value="Tue May 11 11:54:49 2010"/>
+     <xMin value="-335"/>
+     <yMin value="-472"/>
+@@ -12752,15 +12752,15 @@
+     <namerecord nameID="1" platformID="1" platEncID="0" langID="0x0" unicode="True">
+       Samyak Malayalam
+     </namerecord>
+     <namerecord nameID="2" platformID="1" platEncID="0" langID="0x0" unicode="True">
+       Medium
+     </namerecord>
+     <namerecord nameID="3" platformID="1" platEncID="0" langID="0x0" unicode="True">
+-      FontForge 2.0 : Samyak Malayalam : 23-6-2015
++      FontForge 2.0 : Samyak Malayalam : 25-6-2015
+     </namerecord>
+     <namerecord nameID="4" platformID="1" platEncID="0" langID="0x0" unicode="True">
+       Samyak Malayalam
+     </namerecord>
+     <namerecord nameID="5" platformID="1" platEncID="0" langID="0x0" unicode="True">
+       Original Version 1.00 (2005)
+     </namerecord>
+@@ -12810,15 +12810,15 @@
+     <namerecord nameID="1" platformID="3" platEncID="1" langID="0x409">
+       Samyak Malayalam
+     </namerecord>
+     <namerecord nameID="2" platformID="3" platEncID="1" langID="0x409">
+       Medium
+     </namerecord>
+     <namerecord nameID="3" platformID="3" platEncID="1" langID="0x409">
+-      FontForge 2.0 : Samyak Malayalam : 23-6-2015
++      FontForge 2.0 : Samyak Malayalam : 25-6-2015
+     </namerecord>
+     <namerecord nameID="4" platformID="3" platEncID="1" langID="0x409">
+       Samyak Malayalam
+     </namerecord>
+     <namerecord nameID="5" platformID="3" platEncID="1" langID="0x409">
+       Original Version 1.00 (2005)
+     </namerecord>