Fix crash caused by non-numeric shortcut app IDs

Applications such as Lutris create Steam shortcuts that use non-numeric
app IDs. Handle the app IDs gracefully by logging and skipping them
instead of crashing.

Fixes #147

CHANGELOG.md

@@ -9,6 +9,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 ### Fixed
  - Fix Wine crash on newer Steam Runtime installations due to renamed runtime executable
  - Fix graphical Wine applications crashing on Wayland
+ - Fix Protontricks crash caused by Steam shortcuts created by 3rd party applications such as Lutris
 
 ## [1.8.1] - 2022-03-20
 ### Added

src/protontricks/steam.py

@@ -1022,7 +1022,15 @@ def get_custom_windows_shortcuts(steam_path):
         shortcut_id = int(shortcut_id)
 
         if "appid" in shortcut_data:
-            appid = shortcut_data["appid"] & 0xffffffff
+            try:
+                appid = shortcut_data["appid"] & 0xffffffff
+            except TypeError:
+                logger.info(
+                    "Skipping unrecognized non-Steam shortcut with app ID "
+                    "'%s'",
+                    shortcut_data["appid"]
+                )
+                continue
         else:
             appid = get_appid_from_shortcut(
                 target=shortcut_data["exe"], name=shortcut_data["appname"]

tests/conftest.py

@@ -194,14 +194,15 @@ def shortcut_factory(steam_dir, steam_user):
     """
     shortcuts_by_user = defaultdict(list)
 
-    def func(install_dir, name, steamid64=None, appid_in_vdf=False):
+    def func(
+            install_dir, name, steamid64=None, appid_in_vdf=False, appid=None):
         if not steamid64:
             steamid64 = steam_user
 
         # Update shortcuts.vdf first
         steamid3 = int(steamid64) & 0xffffffff
         shortcuts_by_user[steamid3].append({
-            "install_dir": install_dir, "name": name
+            "install_dir": install_dir, "name": name, "appid": appid
         })
 
         shortcut_path = (
@@ -213,13 +214,14 @@ def func(install_dir, name, steamid64=None, appid_in_vdf=False):
         for shortcut_data in shortcuts_by_user[steamid3]:
             install_dir_ = shortcut_data["install_dir"]
             name_ = shortcut_data["name"]
+            appid_ = shortcut_data["appid"]
 
             entry = {
                 "AppName": name_,
                 "StartDir": install_dir_,
                 "exe": str(Path(install_dir_) / name_)
             }
-            # Derive the shortcut ID
+            # Derive the shortcut ID like Steam would
             crc_data = b"".join([
                 entry["exe"].encode("utf-8"),
                 entry["AppName"].encode("utf-8")
@@ -231,15 +233,21 @@ def func(install_dir, name, steamid64=None, appid_in_vdf=False):
             if appid_in_vdf:
                 # Store the app ID in `shortcuts.vdf`. This is similar
                 # in behavior to newer Steam releases.
-                entry["appid"] = ~(result ^ 0xffffffff)
+                if appid_ is None:
+                    entry["appid"] = ~(result ^ 0xffffffff)
+                else:
+                    # For pre-determined app IDs, such as those created by
+                    # Lutris, use them as-is
+                    entry["appid"] = appid_
 
             data["shortcuts"][str(shortcut_id)] = entry
 
         shortcut_path.write_bytes(vdf.binary_dumps(data))
 
-        appid = get_appid_from_shortcut(
-            target=str(Path(install_dir) / name), name=name
-        )
+        if not appid:
+            appid = get_appid_from_shortcut(
+                target=str(Path(install_dir) / name), name=name
+            )
 
         # Create the fake prefix
         (steam_dir / "steamapps" / "compatdata" / str(appid) / "pfx").mkdir(

tests/test_steam.py

@@ -900,6 +900,40 @@ def test_get_custom_windows_shortcuts_read_vdf(
         assert shortcut_apps[0].name == "Non-Steam shortcut: fakegame.exe"
         assert shortcut_apps[0].appid == 4149337689
 
+    @pytest.mark.usefixtures("verbose_logging")
+    def test_get_custom_windows_shortcuts_non_numeric_appid(
+            self, steam_dir, shortcut_factory, caplog):
+        """
+        Retrieve custom Windows shortcuts when one of the contained shortcuts
+        has a non-numeric app ID. This is usually the case for app IDs created
+        with 3rd party applications such as Lutris.
+        """
+        # This won't be reported by Protontricks
+        shortcut_factory(
+            install_dir="/usr/bin", name="lutris",
+            appid_in_vdf=True, appid="lutris-fake-game"
+        )
+        shortcut_factory(
+            install_dir="fake/path/", name="fakegame.exe", appid_in_vdf=True
+        )
+
+        shortcut_apps = get_custom_windows_shortcuts(steam_dir)
+
+        assert len(shortcut_apps) == 1
+        assert shortcut_apps[0].name == "Non-Steam shortcut: fakegame.exe"
+
+        # The non-numeric app ID was logged
+        record = next(
+            record for record in caplog.records
+            if "Skipping unrecognized" in record.message
+        )
+
+        assert record.levelname == "INFO"
+        assert (
+            "Skipping unrecognized non-Steam shortcut with "
+            "app ID 'lutris-fake-game'" in record.message
+        )
+
 
 class TestIsSteamDeck:
     def test_not_steam_deck(self):