fix(updater): fix appimage extraction (#784)

* fix updater on linux

* review changes

* Apply suggestions from code review

* change file

---------

Co-authored-by: Kris Krolak <krzysiek.krolak@gmail.com>

.changes/updater-appimage.md

@@ -0,0 +1,5 @@
+---
+"updater": patch
+---
+
+Fix updater failing to extract the AppImage resulting in failing to update and also deleting the current version. 

plugins/updater/Cargo.toml

@@ -34,7 +34,7 @@ tar = "0.4"
 [target."cfg(target_os = \"windows\")".dependencies]
 zip = { version = "0.6", default-features = false }
 
-[target."cfg(target_os = \"macos\")".dependencies]
+[target."cfg(any(target_os = \"macos\", target_os = \"linux\"))".dependencies]
 flate2 = "1.0.27"
 
 [dev-dependencies]

plugins/updater/src/error.rs

@@ -62,6 +62,8 @@ pub enum Error {
     /// Temp dir is not on same mount mount. This prevents our updater to rename the AppImage to a temp file.
     #[error("temp directory is not on the same mount point as the AppImage")]
     TempDirNotOnSameMountPoint,
+    #[error("binary for the current target not found in the archive")]
+    BinaryNotFoundInAcrhive,
     #[error(transparent)]
     Http(#[from] http::Error),
 }

plugins/updater/src/updater.rs

@@ -600,6 +600,7 @@ impl Update {
         target_os = "openbsd"
     ))]
     fn install_inner(&self, bytes: Vec<u8>) -> Result<()> {
+        use flate2::read::GzDecoder;
         use std::{
             ffi::OsStr,
             os::unix::fs::{MetadataExt, PermissionsExt},
@@ -632,7 +633,8 @@ impl Update {
 
                     // extract the buffer to the tmp_dir
                     // we extract our signed archive into our final directory without any temp file
-                    let mut archive = tar::Archive::new(archive);
+                    let decoder = GzDecoder::new(archive);
+                    let mut archive = tar::Archive::new(decoder);
                     for mut entry in archive.entries()?.flatten() {
                         if let Ok(path) = entry.path() {
                             if path.extension() == Some(OsStr::new("AppImage")) {
@@ -646,8 +648,10 @@ impl Update {
                             }
                         }
                     }
+                    // if we have not returned early we should restore the backup
+                    std::fs::rename(tmp_app_image, &self.extract_path)?;
 
-                    return Ok(());
+                    return Err(Error::BinaryNotFoundInAcrhive);
                 }
             }
         }