Fix/macos py2app libsharpyuv (shlomif#587)

* Bundle libsharpyuv for macOS py2app build

py2app doesn't rewrite @rpath load commands, so libwebp's dependency
on libsharpyuv (split out since webp 1.3) goes missing from the app
bundle and PIL fails to import at launch. Bundle and patch it
explicitly, same as the freecell-solver lib.

* Re-sign macOS bundle after post-py2app dylib patching

install_name_tool invalidates py2app's ad-hoc signature, so a bundle
patched after signing (e.g. the libsharpyuv fix, or the existing
fc-solve rpath fix) gets silently SIGKILLed by macOS on launch. Verified
locally: without this, the fixed app dies with no output at all: the
patched dylib breaks the code signature seal.

Author: bwrightkc

setup_osx.py

@@ -6,7 +6,7 @@
 import os
 import shutil
 import sys
-from subprocess import call
+from subprocess import CalledProcessError, call, check_output
 
 from pysollib.settings import PACKAGE, VERSION
 
@@ -36,6 +36,19 @@
     SOLVER_LIB_PATH = None
     SOLVER = []
 
+# libwebp (a Pillow dependency) depends on libsharpyuv via a bare
+# @rpath reference that py2app's dependency walker doesn't follow.
+# Bundle it explicitly, same as the solver lib above.
+SHARPYUV_LIB_PATH = None
+try:
+    _webp_prefix = check_output(
+        ["brew", "--prefix", "webp"]).decode().strip()
+    _candidate = os.path.join(_webp_prefix, "lib", "libsharpyuv.0.dylib")
+    if os.path.exists(_candidate):
+        SHARPYUV_LIB_PATH = _candidate
+except (OSError, CalledProcessError):
+    pass
+
 GETINFO_STRING = "PySol Fan Club Edition \
                 %s %s, (C) 1998-2003 Markus F.X.J Oberhumer \
                 (C) 2006-2007 Skomoroh" % (PACKAGE, VERSION)
@@ -55,7 +68,8 @@
 DATA_FILES = ['docs', 'data', 'locale', 'scripts', 'COPYING', 'README.md',
               ] + SOLVER
 RESOURCES = []
-FRAMEWORKS = [SOLVER_LIB_PATH] if SOLVER_LIB_PATH else []
+FRAMEWORKS = ([SOLVER_LIB_PATH] if SOLVER_LIB_PATH else []) + \
+             ([SHARPYUV_LIB_PATH] if SHARPYUV_LIB_PATH else [])
 # with argv_emulation=True, the app window is not shown when launched
 OPTIONS = dict(argv_emulation=False,
                emulate_shell_environment=True,
@@ -84,3 +98,27 @@
          @executable_path/../Frameworks/libfreecell-solver.0.dylib fc-solve",
          shell=True
          )
+    os.chdir(top)
+
+# Point libwebp at the bundled libsharpyuv instead of its broken
+# original rpath.
+if SHARPYUV_LIB_PATH and "py2app" in sys.argv:
+    frameworks_dir = os.path.join(
+        top, 'dist', '%s.app' % PACKAGE, 'Contents', 'Frameworks')
+    for name in os.listdir(frameworks_dir):
+        if name.startswith('libwebp'):
+            call([
+                'install_name_tool', '-change',
+                '@rpath/libsharpyuv.0.dylib',
+                '@executable_path/../Frameworks/libsharpyuv.0.dylib',
+                os.path.join(frameworks_dir, name),
+                ])
+
+# install_name_tool invalidates py2app's ad-hoc signature above, and
+# macOS refuses to launch a bundle whose seal doesn't match its
+# contents. Re-sign after any post-processing.
+if (SOLVER or SHARPYUV_LIB_PATH) and "py2app" in sys.argv:
+    call([
+        'codesign', '--force', '--deep', '--sign', '-',
+        os.path.join(top, 'dist', '%s.app' % PACKAGE),
+        ])