Fix the finding of pixbuf loaders on Windows

Author: RedFantom

.appveyor.yml

@@ -24,7 +24,7 @@ install:
   # Add %PYTHON% to the path for libffi-7.dll
   - set PATH=%PYTHON%;C:\msys64\mingw64\lib;%PATH%
 build_script:
-  - "%PYTHON%\\python.exe setup.py build bdist_wheel"
+  - "%PYTHON%\\python.exe -u setup.py build bdist_wheel"
   # Simplify PATH so as to test binary distribution
   - set PATH=C:\WINDOWS\system32;C:\WINDOWS
 test_script:
@@ -35,7 +35,7 @@ deploy:
   provider: GitHub
   auth_token:
     secure: QimY++/91urL/oMJL/q2zYFqc1C7747HguEaIbPQovtC3zG8CK+TiCmFOCXy1D6e
-  artifact: "/dist/*.whl"
+  artifact: "dist/*.whl"
   draft: false
   prerelease: false
   force_update: true

setup.py

@@ -52,11 +52,12 @@ def run(self):
     import subprocess as sp
     from typing import List, Optional
 
-    dependencies = ["pango", "cmake", "gtk2", "glib2", "tk", "toolchain"]
+    dependencies = ["pango", "cmake", "gtk2", "glib2", "tk", "toolchain", "libffi"]
 
     for dep in dependencies:
         printf("Installing dependency {}...".format(dep), end=" ")
-        sp.call(["pacman", "--needed", "--noconfirm", "-S", "mingw-w64-x86_64-{}".format(dep)], stdout=sp.PIPE)
+        sp.call(["pacman", "--needed", "--noconfirm", "-S", "mingw-w64-x86_64-{}".format(dep)],
+                stdout=sp.PIPE, stderr=sp.PIPE)
         printf("Done.")
     sp.call(["cmake", ".", "-G", "MinGW Makefiles"])
     sp.call(["mingw32-make"])
@@ -157,12 +158,23 @@ def copy_to_target(self, target: str):
                     shutil.copyfile(p, os.path.join(target, os.path.basename(p)))
 
     specials={
-        "libpixmap.dll": "/lib/gtk-2.0/2.10.0/engines/", 
-        "libwimp.dll": "/lib/gtk-2.0/2.10.0/engines/",
-        "loaders.cache": "/lib/gdk-pixbuf-2.0/2.10.0/"}  # loaders.cache is used to specify abspaths to the loaders
+        "libpixmap.dll": "lib/gtk-2.0/2.10.0/engines/",
+        "libwimp.dll": "lib/gtk-2.0/2.10.0/engines/",
+        "loaders.cache": "lib/gdk-pixbuf-2.0/2.10.0/"}  # loaders.cache is used to specify abspaths to the loaders
     specials.update({"libpixbufloader-{}.dll".format(fmt): "/lib/gdk-pixbuf-2.0/2.10.0/loaders/"
                      for fmt in ["ani", "bmp", "gif", "icns", "ico", "jpeg", "png", "pnm", "qtif", "svg", "tga", "tiff", "xbm", "xpm"]})
     DependencyWalker("libgttk.dll", specials=specials).copy_to_target("gttk")
+
+    # If loaders.cache is not found, it must be generated
+    cache_file = os.path.join("gttk", specials["loaders.cache"], "loaders.cache")
+    if not os.path.exists(cache_file) or os.path.getsize(cache_file) < 1024:  # Minimum expected file size
+        print("Creating loaders.cache file...")
+        with open("loaders.cache", "wb") as fo:
+            sp.call(["gdk-pixbuf-query-loaders"], stdout=fo)
+        shutil.copyfile("loaders.cache", cache_file)
+        with open(cache_file) as fi:
+            print("gdk-pixbuf-query-loaders gave {} lines of output".format(len(fi.readlines())))
+
     kwargs = {"package_data": {"gttk": ["*.dll", "pkgIndex.tcl", "gttk.tcl"] + ["{}/{}".format(dir.strip("/"), base) for base, dir in specials.items()]}}
 
 else: