metadata: Drop unreliable mime-type

Only use a reliable mime-type. This requires that we load images earlier
in the pipe.

This also fixes warnings about mime types not being available on network
drives like SMB.

Fixes #513
Issue #534

news.d/50.alpha/fixed-wrong-image-format

@@ -0,0 +1 @@
+Showing wrong mime type in error message if the file ending for an image is wrong.

src/decoder.rs

@@ -124,7 +124,11 @@ impl UpdateSender {
     }
 
     pub fn send_error(&self, err: glycin::ErrorCtx) {
-        if err.unsupported_format().is_some() {
+        if let Some(mime_type) = err.unsupported_format() {
+            let mut metadata = Metadata::default();
+            metadata.set_mime_type(mime_type);
+
+            self.send(DecoderUpdate::Metadata(Box::new(metadata)));
             self.send(DecoderUpdate::SpecificError(
                 DecoderError::UnsupportedFormat,
             ));
@@ -150,6 +154,7 @@ pub struct Decoder {
 enum FormatDecoder {
     Glycin(Glycin),
     Svg(Svg),
+    Failed,
 }
 
 impl Decoder {
@@ -159,7 +164,6 @@ impl Decoder {
     /// The renderer should listen to updates from the returned receiver.
     pub async fn new(
         file: gio::File,
-        mime_type: Option<String>,
         tiles: Arc<SharedFrameBuffer>,
     ) -> (Self, mpsc::Receiver<DecoderUpdate>) {
         let (sender, receiver) = mpsc::unbounded();
@@ -167,7 +171,26 @@ impl Decoder {
         let update_sender = UpdateSender { sender };
         tiles.set_update_sender(update_sender.clone());
 
-        let format_decoder = Self::format_decoder(update_sender.clone(), file, mime_type, tiles);
+        log::trace!("Setting up loader");
+        let mut loader = glycin::Loader::new(file);
+        loader.apply_transformations(false);
+
+        let image = match loader.load().await {
+            Ok(image) => image,
+            Err(err) => {
+                update_sender.send_error(err);
+                return (
+                    Self {
+                        decoder: FormatDecoder::Failed,
+                        update_sender,
+                    },
+                    receiver,
+                );
+            }
+        };
+
+        let format_decoder = Self::format_decoder(update_sender.clone(), image, tiles);
+
         let decoder = Self {
             decoder: format_decoder,
             update_sender,
@@ -178,20 +201,19 @@ impl Decoder {
 
     fn format_decoder(
         update_sender: UpdateSender,
-        file: gio::File,
+        image: glycin::Image,
-        mime_type: Option<String>,
         tiles: Arc<SharedFrameBuffer>,
     ) -> FormatDecoder {
-        if let Some(mime_type) = mime_type {
+        let mime_type = image.mime_type().to_string();
-            // Known things we want to match here are
-            // - image/svg+xml
-            // - image/svg+xml-compressed
-            if mime_type.split('+').next() == Some("image/svg") {
-                return FormatDecoder::Svg(Svg::new(file, update_sender, tiles));
-            }
-        }
 
-        FormatDecoder::Glycin(Glycin::new(file, update_sender, tiles))
+        // Known things we want to match here are
+        // - image/svg+xml
+        // - image/svg+xml-compressed
+        if mime_type.split('+').next() == Some("image/svg") {
+            return FormatDecoder::Svg(Svg::new(image, update_sender, tiles));
+        } else {
+            FormatDecoder::Glycin(Glycin::new(image, update_sender, tiles))
+        }
     }
 
     /// Request missing tiles

src/decoder/formats/glycin_proxy.rs

@@ -42,22 +42,12 @@ impl Drop for Glycin {
 }
 
 impl Glycin {
-    pub fn new(file: gio::File, updater: UpdateSender, tiles: Arc<SharedFrameBuffer>) -> Self {
+    pub fn new(image: glycin::Image, updater: UpdateSender, tiles: Arc<SharedFrameBuffer>) -> Self {
-        let cancellable = gio::Cancellable::new();
+        let cancellable = image.cancellable();
-        let cancellable_ = cancellable.clone();
 
         let (next_frame_send, next_frame_recv) = async_channel::bounded(2);
 
         updater.clone().spawn_error_handled(async move {
-            log::trace!("Setting up loader");
-            let mut loader = glycin::Loader::new(file);
-            loader.apply_transformations(false);
-
-            loader.cancellable(cancellable_);
-
-            let image = loader.load().await?;
-            log::trace!("Image info received");
-
             let mut metadata: Metadata = Metadata::default();
             metadata.set_image_info(image.details().clone());
             metadata.set_mime_type(image.mime_type().to_string());

src/decoder/formats/svg.rs

@@ -61,21 +61,14 @@ impl Drop for Svg {
 }
 
 impl Svg {
-    pub fn new(file: gio::File, updater: UpdateSender, tiles: Arc<SharedFrameBuffer>) -> Self {
+    pub fn new(image: glycin::Image, updater: UpdateSender, tiles: Arc<SharedFrameBuffer>) -> Self {
         let current_request: Arc<std::sync::RwLock<Request>> = Default::default();
         let request_store = current_request.clone();
-        let cancellable = gio::Cancellable::new();
+        let cancellable = image.cancellable();
         let cancellable_ = cancellable.clone();
         let (wakeup, wakeup_resv) = mpsc::unbounded();
 
         updater.clone().spawn_error_handled(async move {
-            log::trace!("Setting up SVG loader");
-            let mut loader = glycin::Loader::new(file);
-
-            loader.cancellable(cancellable.clone());
-
-            let image = loader.load().await?;
-
             let mut metadata: Metadata = Metadata::default();
             metadata.set_image_info(image.details().clone());
             metadata.set_mime_type(image.mime_type().to_string());

src/metadata.rs

@@ -116,25 +116,11 @@ impl Metadata {
         self.mime_type.clone()
     }
 
-    /// Unreliable mime type
-    ///
-    /// Before the image is successfully loaded, this mime type might be wrong
-    /// since it is not yet based on the more complex mime type detection used
-    /// by glyin.
-    pub fn unreliable_mime_type(&self) -> Option<String> {
-        self.mime_type().or_else(|| {
-            self.file_info
-                .as_ref()
-                .and_then(|x| x.mime_type.as_ref())
-                .map(|x| x.to_string())
-        })
-    }
-
     pub fn format_name(&self) -> Option<String> {
         self.image_info
             .as_ref()
             .and_then(|x| x.info_format_name().map(|x| x.to_string()))
-            .or_else(|| self.unreliable_mime_type())
+            .or_else(|| self.mime_type())
     }
 
     pub fn alpha_channel(&self) -> Option<bool> {

src/metadata/file.rs

@@ -23,7 +23,6 @@ const ATTRIBUTE_HOST_PATH: &str = "xattr::document-portal.host-path";
 pub struct FileInfo {
     pub(super) display_name: glib::GString,
     pub(super) file_size: Option<u64>,
-    pub(super) mime_type: Option<glib::GString>,
     pub(super) created: Option<glib::DateTime>,
     pub(super) modified: Option<glib::DateTime>,
     pub(super) host_path: Option<glib::GString>,
@@ -50,9 +49,6 @@ impl FileInfo {
         Ok(Self {
             display_name: file_info.display_name(),
             file_size,
-            mime_type: file_info
-                .content_type()
-                .and_then(|x| gio::content_type_get_mime_type(&x)),
             created: file_info.creation_date_time(),
             modified: file_info.modification_date_time(),
             host_path: file_info.attribute_as_string(ATTRIBUTE_HOST_PATH),

src/widgets/image/loading.rs

@@ -32,17 +32,22 @@ impl imp::LpImage {
     }
 
     /// Set filename after filename changed
-    async fn set_file_changed(&self, file: &gio::File) {
+    async fn set_file_changed(&self, old_file: &gio::File, new_file: &gio::File) {
         let obj = self.obj();
-        let prev_mime_type = obj.metadata().unreliable_mime_type();
+        let old_filename_ext = old_file
+            .basename()
+            .map(|x| x.extension().map(|x| x.to_owned()));
+        let new_filename_ext = new_file
+            .basename()
+            .map(|x| x.extension().map(|x| x.to_owned()));
 
-        self.file.replace(Some(file.clone()));
+        self.file.replace(Some(new_file.clone()));
         self.reload_file_info().await;
 
-        // Reload if mime type changed since other decoding path might be responsible
+        // Reload if file extension changed since other decoding path might be responsible
         // now
-        if obj.metadata().unreliable_mime_type() != prev_mime_type {
+        if old_filename_ext != new_filename_ext {
-            obj.load(file).await;
+            obj.load(new_file).await;
             return;
         }
 
@@ -223,6 +228,7 @@ impl imp::LpImage {
                             obj.load(&file).await;
                         });
                     } else {
+                        let old_file = file_a.clone();
                         glib::spawn_future_local(async move {
                             if obj.error().is_some() {
                                 // Tmp files might be renamed quickly after creation. In this case
@@ -230,7 +236,7 @@ impl imp::LpImage {
                                 // Therefore reload on name change loading caused an error.
                                 obj.load(&file).await;
                             } else {
-                                obj.imp().set_file_changed(&file).await;
+                                obj.imp().set_file_changed(&old_file, &file).await;
                             }
                         });
                     }
@@ -365,12 +371,7 @@ impl LpImage {
         // Reset background color for reloads
         imp.set_background_color(None);
 
-        let (decoder, decoder_update) = Decoder::new(
+        let (decoder, decoder_update) = Decoder::new(file.clone(), tiles.clone()).await;
-            file.clone(),
-            self.metadata().unreliable_mime_type(),
-            tiles.clone(),
-        )
-        .await;
 
         let weak_obj = self.downgrade();
         glib::spawn_future_local(async move {

src/widgets/image_page.rs

@@ -231,7 +231,7 @@ impl LpImagePage {
             imp.stack.set_visible_child(&*imp.error_page);
             imp.error_more_info.set_visible(false);
         } else if image.specific_error() == DecoderError::UnsupportedFormat {
-            let mime_type = image.metadata().unreliable_mime_type().unwrap_or_default();
+            let mime_type = image.metadata().mime_type().unwrap_or_default();
             let content_type = gio::content_type_from_mime_type(&mime_type).unwrap_or_default();
             let description = gio::content_type_get_description(&content_type).to_string();