Fix Steam detection for multiple Steam installs

When both Flatpak and non-Flatpak versions of Steam are installed for
the same user, Steam installation detection might return two paths that
correspond to two different installations of Steam.

Ensure that the two paths returned by `find_steam_path` are the same
when Flatpak sandbox is active and Flatpak installation directory is
found.

Refs flathub/com.github.Matoking.protontricks#10

CHANGELOG.md

@@ -8,6 +8,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 ## [Unreleased]
 ### Fixed
  - Fix Wine crash when the Steam application and Protontricks are running at the same time
+ - Fix Steam installation detection when both non-Flatpak and Flatpak versions of Steam are installed for the same user
 
 ## [1.7.0] - 2022-01-08
 ### Changed

src/protontricks/steam.py

@@ -302,15 +302,22 @@ def has_runtime_dir(path):
 
         return None, None
 
-    # If we're inside a Flatpak sandbox,
-    # prioritize Flatpak installation of Steam
-    steam_dirs_to_search = (
-        [".var/app/com.valvesoftware.Steam/data/Steam"] + COMMON_STEAM_DIRS
-        if is_flatpak_sandbox()
-        else COMMON_STEAM_DIRS
-    )
+    if is_flatpak_sandbox():
+        # If we're inside a Flatpak sandbox,
+        # prioritize Flatpak installation of Steam.
+        # In this case, ensure we don't mix steam_root and steam_path
+        # from Flatpak and non-Flatpak installations of Steam.
+        steam_path = \
+            Path.home() / ".var/app/com.valvesoftware.Steam/data/Steam"
+        if has_steamapps_dir(steam_path):
+            logger.info(
+                "Found Steam directory at %s. You can also define Steam "
+                "directory manually using $STEAM_DIR",
+                steam_path
+            )
+            return steam_path, steam_path
 
-    for steam_path in steam_dirs_to_search:
+    for steam_path in COMMON_STEAM_DIRS:
         # The common Steam directories are found inside the home directory
         steam_path = Path.home() / steam_path
         if has_steamapps_dir(steam_path):

tests/conftest.py

@@ -94,6 +94,26 @@ def steam_root(steam_dir):
     yield steam_dir.parent / "root"
 
 
+@pytest.fixture(scope="function")
+def flatpak_sandbox(monkeypatch, tmp_path):
+    """
+    Fake Flatpak sandbox running under Flatpak 1.12.1
+    """
+    flatpak_info_path = tmp_path / "flatpak-info"
+
+    flatpak_info_path.write_text(
+        "[Application]\n"
+        "name=fake.flatpak.Protontricks\n"
+        "\n"
+        "[Instance]\n"
+        "flatpak-version=1.12.1"
+    )
+
+    monkeypatch.setattr(
+        "protontricks.util.FLATPAK_INFO_PATH", str(flatpak_info_path)
+    )
+
+
 @pytest.fixture(scope="function", autouse=True)
 def steam_runtime_dir(steam_dir):
     """

tests/test_steam.py

@@ -388,6 +388,30 @@ def test_find_steam_path_env(
         assert str(steam_paths[0]) == str(custom_path)
         assert str(steam_paths[1]) == str(custom_path)
 
+    def test_find_steam_path_flatpak(
+            self, steam_dir, steam_root, tmp_path, home_dir, flatpak_sandbox,
+            monkeypatch):
+        """
+        Ensure that `steam_path` and `steam_root` both point to the Flatpak
+        installation of Steam if Flatpak installation is found.
+
+        Regression test for flathub/com.github.Matoking.protontricks#10
+        """
+        # Create a symlink to act as the Flatpak installation to keep the test
+        # simple.
+        steam_flatpak_dir = (
+            home_dir / ".var" / "app" / "com.valvesoftware.Steam" / "data"
+            / "Steam"
+        )
+        steam_flatpak_dir.parent.mkdir(parents=True)
+        steam_flatpak_dir.symlink_to(steam_dir)
+
+        # Since Flatpak is enabled, both paths should point to Flatpak
+        steam_path, steam_root = find_steam_path()
+
+        assert str(steam_path) == str(steam_flatpak_dir)
+        assert str(steam_root) == str(steam_flatpak_dir)
+
 
 class TestGetSteamApps:
     def test_get_steam_apps_custom_proton(