Fix Flatpak Apps not getting the profile

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "volt"
-version = "2.2.1"
+version = "2.2.2"
 edition = "2021"
 rust-version = "1.85.1"
 

README.md

@@ -439,7 +439,7 @@ flatpak install --user build/bundles/org.freedesktop.Platform.VulkanLayer.volt-2
 flatpak uninstall --user org.freedesktop.Platform.VulkanLayer.volt
 ```
 
-The launcher detects `flatpak run` and routes through the in-sandbox wrapper:
+The launcher detects `flatpak run` and routes through the in-sandbox wrapper. It also mounts `~/.config/volt-gui` into the sandbox, read-only, or read-write under `--probe`:
 
 ```
 volt -- flatpak run com.example.Game
@@ -451,20 +451,26 @@ There's no Flatpak build of volt-gui itself, only the layer.
 
 ### Without the launcher
 
-Call the wrapper yourself, useful where only the extension is installed:
+Call the wrapper yourself, useful where only the extension is installed. Mount the profiles yourself too. The wrapper runs inside the sandbox and can't do it from there:
 
 ```
-flatpak run --command=/usr/lib/extensions/vulkan/volt/bin/volt-flatpak com.example.Game
-VOLT_CONFIG_NAME=myprofile flatpak run --command=/usr/lib/extensions/vulkan/volt/bin/volt-flatpak com.example.Game
+flatpak run --filesystem=xdg-config/volt-gui:ro --command=/usr/lib/extensions/vulkan/volt/bin/volt-flatpak com.example.Game
+VOLT_CONFIG_NAME=myprofile flatpak run --filesystem=xdg-config/volt-gui:ro --command=/usr/lib/extensions/vulkan/volt/bin/volt-flatpak com.example.Game
 ```
 
-Same line works as a Steam launch option for a Flatpak game:
+A Steam launch option has no room for that flag, so grant it once instead:
+
+```
+flatpak override --user --filesystem=xdg-config/volt-gui:ro com.example.Game
+```
+
+Then the launch option is just the wrapper:
 
 ```
 /usr/lib/extensions/vulkan/volt/bin/volt-flatpak %command%
 ```
 
-Your home directory is mounted into the sandbox, so profiles apply unchanged.
+Without the grant the layer still loads, it just finds no profile and leaves every setting alone. `VOLT_LOG=info` names the path it couldn't read.
 
 ## Profiles, Presets & Options
 

src/volt-gui/database.py

@@ -15,7 +15,7 @@
 from probe import shading_options
 
 
-APP_VERSION: Final[str] = "2.2.1"
+APP_VERSION: Final[str] = "2.2.2"
 APP_AUTHOR: Final[str] = "pythonlover02"
 APP_LICENSE: Final[str] = "GPL 3.0 License"
 APP_DESCRIPTION: Final[str] = "My AMD Adrenaline / NVIDIA Settings Linux Alternative"

src/volt/config.rs

@@ -303,9 +303,16 @@ pub(crate) fn config_path(name: &str) -> PathBuf {
 }
 
 fn read_config(path: &PathBuf) -> Settings {
-    fs::read_to_string(path)
-        .map(|t| parse_settings(&t))
-        .unwrap_or_default()
+    match fs::read_to_string(path) {
+        Ok(text) => parse_settings(&text),
+        Err(e) => {
+            log_at(
+                LogLevel::Warn,
+                &format!("{}: {}, every setting left alone", path.display(), e),
+            );
+            Settings::default()
+        }
+    }
 }
 
 fn load_settings() -> Settings {

src/volt/consts.rs

@@ -38,6 +38,8 @@ pub(crate) const PROBE_FAIL_WARN: &str = "probe write failed, the interface keep
 pub(crate) const FLATPAK_CMD: &str = "flatpak";
 pub(crate) const FLATPAK_RUN: &str = "run";
 pub(crate) const FLATPAK_INJECT: &str = "/usr/lib/extensions/vulkan/volt/bin/volt-flatpak";
+pub(crate) const FLATPAK_CONFIG_RO: &str = "--filesystem=xdg-config/volt-gui:ro";
+pub(crate) const FLATPAK_CONFIG_RW: &str = "--filesystem=xdg-config/volt-gui";
 
 pub(crate) const LOG_FD: i32 = 2;
 pub(crate) const LOG_LEVEL_OFF: i32 = 0;

src/volt/launcher.rs

@@ -17,6 +17,8 @@ use crate::consts::EXIT_EXEC_FAILED;
 use crate::consts::EXIT_OK;
 use crate::consts::EXIT_USAGE;
 use crate::consts::FLATPAK_CMD;
+use crate::consts::FLATPAK_CONFIG_RO;
+use crate::consts::FLATPAK_CONFIG_RW;
 use crate::consts::FLATPAK_INJECT;
 use crate::consts::ENV_PROBE;
 use crate::consts::FLATPAK_RUN;
@@ -120,6 +122,13 @@ fn flatpak_trailing(cmd: &[String]) -> Vec<String> {
         .unwrap_or_default()
 }
 
+fn config_share(probe: bool) -> &'static str {
+    match probe {
+        true => FLATPAK_CONFIG_RW,
+        false => FLATPAK_CONFIG_RO,
+    }
+}
+
 fn build_flatpak_args(
     profile: &str,
     app_id: &str,
@@ -133,6 +142,7 @@ fn build_flatpak_args(
             format!("--command={}", FLATPAK_INJECT),
             format!("--env={}={}", ENV_CONFIG_NAME, profile),
             format!("--env={}={}", ENV_PROBE, probe_value(probe)),
+            config_share(probe).to_string(),
         ],
         flags.to_vec(),
         vec![app_id.to_string()],