update: do not crash on android-26+ XML icon

For example:
res/drawable-v26/icon.xml

Here's the full range of possibilities, we have a lot of work to do:

$ for f in */*.apk; do unzip -l $f |grep -F icon.| grep -Eo 'res/drawable[^/]*'; done | sort -u
res/drawable
res/drawable-anydpi-v21
res/drawable-anydpi-v26
res/drawable-hdpi
res/drawable-hdpi-v11
res/drawable-hdpi-v12
res/drawable-hdpi-v4
res/drawable-hdpi-v5
res/drawable-hdpi-v6
res/drawable-hdpi-v9
res/drawable-large
res/drawable-large-hdpi-v11
res/drawable-large-hdpi-v4
res/drawable-large-ldpi-v4
res/drawable-large-mdpi
res/drawable-large-mdpi-v11
res/drawable-large-v4
res/drawable-large-xhdpi-v11
res/drawable-large-xhdpi-v4
res/drawable-large-xxhdpi-v11
res/drawable-large-xxhdpi-v4
res/drawable-ldpi
res/drawable-ldpi-v11
res/drawable-ldpi-v4
res/drawable-ldpi-v5
res/drawable-ldpi-v6
res/drawable-ldpi-v9
res/drawable-ldrtl-v17
res/drawable-mdpi
res/drawable-mdpi-v11
res/drawable-mdpi-v12
res/drawable-mdpi-v4
res/drawable-mdpi-v5
res/drawable-mdpi-v6
res/drawable-mdpi-v9
res/drawable-nodpi
res/drawable-nodpi-v4
res/drawable-tvdpi-v4
res/drawable-v11
res/drawable-v14
res/drawable-v21
res/drawable-xhdpi
res/drawable-xhdpi-v11
res/drawable-xhdpi-v12
res/drawable-xhdpi-v4
res/drawable-xhdpi-v9
res/drawable-xlarge-hdpi
res/drawable-xlarge-hdpi-v4
res/drawable-xlarge-mdpi
res/drawable-xlarge-mdpi-v4
res/drawable-xlarge-v4
res/drawable-xlarge-xhdpi-v4
res/drawable-xxhdpi
res/drawable-xxhdpi-v11
res/drawable-xxhdpi-v21
res/drawable-xxhdpi-v4
res/drawable-xxhdpi-v9
res/drawable-xxxhdpi
res/drawable-xxxhdpi-v11
res/drawable-xxxhdpi-v4

fdroidserver/update.py

@@ -60,6 +60,7 @@ APK_PERMISSION_PAT = \
 APK_FEATURE_PAT = re.compile(".*name='([^']*)'.*")
 
 screen_densities = ['65534', '640', '480', '320', '240', '160', '120']
+# resolutions must end with 'dpi'
 screen_resolutions = {
     "xxxhdpi": '640',
     "xxhdpi": '480',
@@ -67,7 +68,7 @@ screen_resolutions = {
     "hdpi": '240',
     "mdpi": '160',
     "ldpi": '120',
-    "undefined": '-1',
+    "undefineddpi": '-1',
     "anydpi": '65534',
     "nodpi": '65535'
 }
@@ -1090,7 +1091,7 @@ def _get_apk_icons_src(apkfile, icon_name):
             m = density_re.match(filename)
             if m:
                 folder = m.group(1).split('-')
-                if len(folder) > 1:
+                if len(folder) > 1 and folder[1].endswith('dpi'):
                     density = screen_resolutions[folder[1]]
                 else:
                     density = '160'