Merge commit from fork

plugins/updater/src/commands.rs

@@ -46,7 +46,6 @@ pub(crate) async fn check<R: Runtime>(
     timeout: Option<u64>,
     proxy: Option<String>,
     target: Option<String>,
-    allow_downgrades: Option<bool>,
 ) -> Result<Option<Metadata>> {
     let mut builder = webview.updater_builder();
     if let Some(headers) = headers {
@@ -64,9 +63,6 @@ pub(crate) async fn check<R: Runtime>(
     if let Some(target) = target {
         builder = builder.target(target);
     }
-    if allow_downgrades.unwrap_or(false) {
-        builder = builder.version_comparator(|current, update| update.version != current);
-    }
 
     let updater = builder.build()?;
     let update = updater.check().await?;

plugins/updater/src/config.rs

@@ -133,6 +133,19 @@ pub struct Config {
     ///
     /// The default value of this flag is `false`.
     pub require_signed_version: bool,
+    /// Allow the updater to install a release whose version is not newer than the
+    /// currently running one, changing the version check from "must be newer" to
+    /// "must be different".
+    ///
+    /// Note that the updater only verifies the signature of the downloaded artifact,
+    /// not the version advertised by the update endpoint, so enabling this removes the
+    /// only guard against installing a previously released (and validly signed) version.
+    ///
+    /// Ignored when the application sets a custom
+    /// [`Builder::default_version_comparator`](crate::Builder::default_version_comparator).
+    ///
+    /// The default value of this flag is `false`.
+    pub allow_downgrades: bool,
     /// The Windows configuration for the updater.
     pub windows: Option<WindowsConfig>,
 }
@@ -156,6 +169,8 @@ impl<'de> Deserialize<'de> for Config {
             pub pubkey: String,
             #[serde(default, alias = "require-signed-version")]
             pub require_signed_version: bool,
+            #[serde(default, alias = "allow-downgrades")]
+            pub allow_downgrades: bool,
             pub windows: Option<WindowsConfig>,
         }
 
@@ -174,6 +189,7 @@ impl<'de> Deserialize<'de> for Config {
             endpoints: config.endpoints,
             pubkey: config.pubkey,
             require_signed_version: config.require_signed_version,
+            allow_downgrades: config.allow_downgrades,
             windows: config.windows,
         })
     }

plugins/updater/src/lib.rs

@@ -98,6 +98,11 @@ impl<R: Runtime, T: Manager<R>> UpdaterExt<R> for T {
 
         builder.version_comparator = version_comparator.clone();
 
+        // a comparator set by the application takes precedence over the configuration
+        if builder.version_comparator.is_none() && config.allow_downgrades {
+            builder = builder.version_comparator(|current, update| update.version != current);
+        }
+
         #[cfg(any(
             target_os = "linux",
             target_os = "dragonfly",