Save inline images displayed via MIME Content-ID: Closes #7475

Some reorganization of how data: URIs are assembled and injected
into the document.

Also, mild improvement to the GMime bindings.

bindings/vapi/gmime-2.6.vapi

@@ -804,19 +804,19 @@ namespace GMime {
 		[CCode (cname = "g_mime_part_get_best_content_encoding")]
 		public GMime.ContentEncoding get_best_content_encoding (GMime.EncodingConstraint constraint);
 		[CCode (cname = "g_mime_part_get_content_description")]
-		public unowned string get_content_description ();
+		public unowned string? get_content_description ();
 		[CCode (cname = "g_mime_part_get_content_encoding")]
 		public GMime.ContentEncoding get_content_encoding ();
 		[CCode (cname = "g_mime_part_get_content_id")]
-		public unowned string get_content_id ();
+		public unowned string? get_content_id ();
 		[CCode (cname = "g_mime_part_get_content_location")]
-		public unowned string get_content_location ();
+		public unowned string? get_content_location ();
 		[CCode (cname = "g_mime_part_get_content_md5")]
-		public unowned string get_content_md5 ();
+		public unowned string? get_content_md5 ();
 		[CCode (cname = "g_mime_part_get_content_object")]
-		public unowned GMime.DataWrapper get_content_object ();
+		public unowned GMime.DataWrapper? get_content_object ();
 		[CCode (cname = "g_mime_part_get_filename")]
-		public unowned string get_filename ();
+		public unowned string? get_filename ();
 		[CCode (cname = "g_mime_part_set_content_description")]
 		public void set_content_description (string description);
 		[CCode (cname = "g_mime_part_set_content_encoding")]

bindings/vapi/gmime-2.6/gmime-2.6.metadata

@@ -11,7 +11,13 @@ g_mime_object_get_content_type_parameter nullable="1"
 g_mime_object_to_string transfer_ownership="1"
 g_mime_param_next name="get_next"
 g_mime_parser_construct_message nullable="1"
+g_mime_part_get_content_description nullable="1"
+g_mime_part_get_content_location nullable="1"
+g_mime_part_get_content_id nullable="1"
+g_mime_part_get_content_md5 nullable="1"
+g_mime_part_get_content_object nullable="1"
 g_mime_part_get_content_part nullable="1"
+g_mime_part_get_filename nullable="1"
 g_mime_signer_next name="get_next"
 g_mime_stream_mem_new_with_buffer.buffer is_array="1" array_length_pos="1.0" type_name="uint8[]"
 g_mime_stream_mem_new_with_buffer.len hidden="1"

src/client/geary-controller.vala

@@ -1492,12 +1492,13 @@ public class GearyController : Geary.BaseObject {
         }
     }
     
-    private void on_save_buffer_to_file(string filename, Geary.Memory.Buffer buffer) {
+    private void on_save_buffer_to_file(string? filename, Geary.Memory.Buffer buffer) {
         Gtk.FileChooserDialog dialog = new Gtk.FileChooserDialog(null, main_window, Gtk.FileChooserAction.SAVE,
             Stock._CANCEL, Gtk.ResponseType.CANCEL, Stock._SAVE, Gtk.ResponseType.ACCEPT, null);
         if (last_save_directory != null)
             dialog.set_current_folder(last_save_directory.get_path());
-        dialog.set_current_name(filename);
+        if (!Geary.String.is_empty(filename))
+            dialog.set_current_name(filename);
         dialog.set_do_overwrite_confirmation(true);
         dialog.confirm_overwrite.connect(on_confirm_overwrite);
         dialog.set_create_folders(true);

src/client/util/util-webkit.vala

@@ -400,3 +400,50 @@ public string resolve_nesting(string text, string[] values) {
     }
 }
 
+// Returns a URI suitable for an IMG SRC attribute (or elsewhere, potentially) that is the
+// memory buffer unpacked into a Base-64 encoded data: URI
+public string assemble_data_uri(string mimetype, Geary.Memory.Buffer buffer) {
+    // attempt to use UnownedBytesBuffer to avoid memcpying a potentially huge buffer only to
+    // free it when the encoding operation is completed
+    string base64;
+    Geary.Memory.UnownedBytesBuffer? unowned_bytes = buffer as Geary.Memory.UnownedBytesBuffer;
+    if (unowned_bytes != null)
+        base64 = Base64.encode(unowned_bytes.to_unowned_uint8_array());
+    else
+        base64 = Base64.encode(buffer.get_uint8_array());
+    
+    return "data:%s;base64,%s".printf(mimetype, base64);
+}
+
+// Turns the data: URI created by assemble_data_uri() back into its components.  The returned
+// buffer is decoded.
+//
+// TODO: Return mimetype
+public bool dissasemble_data_uri(string uri, out Geary.Memory.Buffer? buffer) {
+    buffer = null;
+    
+    if (!uri.has_prefix("data:"))
+        return false;
+    
+    // count from semicolon past encoding type specifier
+    int start_index = uri.index_of(";");
+    if (start_index <= 0)
+        return false;
+    
+    // watch for string termination to avoid overflow
+    int base64_len = "base64,".length;
+    for (int ctr = 0; ctr < base64_len; ctr++) {
+        if (uri[start_index++] == Geary.String.EOS)
+            return false;
+    }
+    
+    // avoid a memory copy of the substring by manually calculating the start address
+    uint8[] bytes = Base64.decode((string) (((char *) uri) + start_index));
+    
+    // transfer ownership of the byte array directly to the Buffer; this prevents an
+    // unnecessary copy
+    buffer = new Geary.Memory.ByteBuffer.take((owned) bytes, bytes.length);
+    
+    return true;
+}
+

src/client/views/conversation-viewer.vala

@@ -23,7 +23,7 @@ public class ConversationViewer : Gtk.Box {
     private const string MESSAGE_CONTAINER_ID = "message_container";
     private const string SELECTION_COUNTER_ID = "multiple_messages";
     private const string SPINNER_ID = "spinner";
-    private const string REPLACED_IMAGE_CLASS = "replaced_inline_image";
+    private const string DATA_IMAGE_CLASS = "data_inline_image";
     
     private enum SearchState {
         // Search/find states.
@@ -94,7 +94,7 @@ public class ConversationViewer : Gtk.Box {
     public signal void save_attachments(Gee.List<Geary.Attachment> attachment);
     
     // Fired when the user wants to save an image buffer to disk
-    public signal void save_buffer_to_file(string filename, Geary.Memory.Buffer buffer);
+    public signal void save_buffer_to_file(string? filename, Geary.Memory.Buffer buffer);
     
     // Fired when the user clicks the edit draft button.
     public signal void edit_draft(Geary.Email message);
@@ -563,7 +563,7 @@ public class ConversationViewer : Gtk.Box {
         bind_event(web_view, ".email .compressed_note", "click", (Callback) on_body_toggle_clicked, this);
         bind_event(web_view, ".attachment_container .attachment", "click", (Callback) on_attachment_clicked, this);
         bind_event(web_view, ".attachment_container .attachment", "contextmenu", (Callback) on_attachment_menu, this);
-        bind_event(web_view, "." + REPLACED_IMAGE_CLASS, "contextmenu", (Callback) on_replaced_image_menu, this);
+        bind_event(web_view, "." + DATA_IMAGE_CLASS, "contextmenu", (Callback) on_data_image_menu, this);
         bind_event(web_view, ".remote_images .show_images", "click", (Callback) on_show_images, this);
         bind_event(web_view, ".remote_images .show_from", "click", (Callback) on_show_images_from, this);
         bind_event(web_view, ".remote_images .close_show_images", "click", (Callback) on_close_show_images, this);
@@ -693,46 +693,7 @@ public class ConversationViewer : Gtk.Box {
             return null;
         
         return "<img alt=\"%s\" class=\"%s\" src=\"%s\" />".printf(
-            filename, REPLACED_IMAGE_CLASS, assemble_replaced_image_uri(mimetype, buffer));
+            filename, DATA_IMAGE_CLASS, assemble_data_uri(mimetype, buffer));
-    }
-    
-    private static string assemble_replaced_image_uri(string mimetype, Geary.Memory.Buffer buffer) {
-        // attempt to use UnownedBytesBuffer to avoid memcpying a potentially huge buffer only to
-        // free it when the encoding operation is completed
-        string base64;
-        Geary.Memory.UnownedBytesBuffer? unowned_bytes = buffer as Geary.Memory.UnownedBytesBuffer;
-        if (unowned_bytes != null)
-            base64 = Base64.encode(unowned_bytes.to_unowned_uint8_array());
-        else
-            base64 = Base64.encode(buffer.get_uint8_array());
-        
-        return "data:%s;base64,%s".printf(mimetype, base64);
-    }
-    
-    // Turns the data: URI created by assemble_replaced_image_uri() back into its components.  The
-    // returned buffer is decoded.
-    //
-    // TODO: return mimetype
-    private static bool dissasemble_replaced_image_uri(string uri, out Geary.Memory.Buffer? buffer) {
-        buffer = null;
-        
-        if (!uri.has_prefix("data:"))
-            return false;
-        
-        // count from semicolon past encoding type specifier
-        int start_index = uri.index_of(";");
-        if (start_index <= 0)
-            return false;
-        start_index += "base64,".length;
-        
-        // avoid a memory copy of the substring by manually calculating the start address
-        uint8[] bytes = Base64.decode((string) (((char *) uri) + start_index));
-        
-        // transfer ownership of the byte array directly to the Buffer; this prevents an
-        // unnecessary copy
-        buffer = new Geary.Memory.ByteBuffer.take((owned) bytes, bytes.length);
-        
-        return true;
     }
     
     private void unhide_last_email() {
@@ -1328,17 +1289,17 @@ public class ConversationViewer : Gtk.Box {
             conversation_viewer.show_attachment_menu(email, attachment);
     }
     
-    private static void on_replaced_image_menu(WebKit.DOM.Element element, WebKit.DOM.Event event,
+    private static void on_data_image_menu(WebKit.DOM.Element element, WebKit.DOM.Event event,
         ConversationViewer conversation_viewer) {
         event.stop_propagation();
         
         Geary.Memory.Buffer? buffer;
-        if (!dissasemble_replaced_image_uri(element.get_attribute("src"), out buffer))
+        if (!dissasemble_data_uri(element.get_attribute("src"), out buffer))
             return;
         
-        string filename = element.get_attribute("alt");
+        string? filename = element.get_attribute("alt");
         
-        if (buffer != null && buffer.size > 0 && !Geary.String.is_empty(filename))
+        if (buffer != null && buffer.size > 0)
             conversation_viewer.show_replaced_image_menu(filename, buffer);
     }
     
@@ -1448,7 +1409,7 @@ public class ConversationViewer : Gtk.Box {
         return menu;
     }
     
-    private void show_replaced_image_menu(string filename, Geary.Memory.Buffer buffer) {
+    private void show_replaced_image_menu(string? filename, Geary.Memory.Buffer buffer) {
         image_menu = new Gtk.Menu();
         image_menu.selection_done.connect(() => {
             image_menu = null;
@@ -1634,16 +1595,27 @@ public class ConversationViewer : Gtk.Box {
                     continue;
                 } else if (src.has_prefix("cid:")) {
                     string mime_id = src.substring(4);
+                    
+                    string? filename = message.get_content_filename_by_mime_id(mime_id);
                     Geary.Memory.Buffer image_content = message.get_content_by_mime_id(mime_id);
-                    uint8[] image_data = image_content.get_uint8_array();
+                    Geary.Memory.UnownedBytesBuffer? unowned_buffer =
-
+                        image_content as Geary.Memory.UnownedBytesBuffer;
+                    
                     // Get the content type.
-                    bool uncertain_content_type;
+                    string guess;
-                    string mimetype = ContentType.get_mime_type(ContentType.guess(null, image_data,
+                    if (unowned_buffer != null)
-                        out uncertain_content_type));
+                        guess = ContentType.guess(null, unowned_buffer.to_unowned_uint8_array(), null);
-
+                    else
-                    // Then set the source to a data url.
+                        guess = ContentType.guess(null, image_content.get_uint8_array(), null);
-                    web_view.set_data_url(img, mimetype, image_data);
+                        
+                    string mimetype = ContentType.get_mime_type(guess);
+                    
+                    // Replace the SRC to a data URIm the class to a known label for the popup menu,
+                    // and the ALT to its filename, if supplied
+                    img.set_attribute("src", assemble_data_uri(mimetype, image_content));
+                    img.set_attribute("class", DATA_IMAGE_CLASS);
+                    if (!Geary.String.is_empty(filename))
+                        img.set_attribute("alt", filename);
                 } else if (!src.has_prefix("data:")) {
                     remote_images = true;
                 }
@@ -1838,7 +1810,8 @@ public class ConversationViewer : Gtk.Box {
                 // Set the image preview and insert it into the container.
                 WebKit.DOM.HTMLImageElement img =
                     Util.DOM.select(attachment_table, ".preview img") as WebKit.DOM.HTMLImageElement;
-                web_view.set_image_src(img, attachment.mime_type, attachment.file.get_path(), ATTACHMENT_PREVIEW_SIZE);
+                web_view.set_attachment_src(img, attachment.mime_type, attachment.file.get_path(),
+                    ATTACHMENT_PREVIEW_SIZE);
                 attachment_container.append_child(attachment_table);
             }
 

src/client/views/conversation-web-view.vala

@@ -202,21 +202,27 @@ public class ConversationWebView : WebKit.WebView {
     private void set_icon_src(string selector, string icon_name) {
         try {
             // Load icon.
-            uint8[] icon_content = null;
+            uint8[]? icon_content = null;
             Gdk.Pixbuf? pixbuf = IconFactory.instance.load_symbolic_colored(icon_name, 16);
             if (pixbuf != null)
                 pixbuf.save_to_buffer(out icon_content, "png"); // Load as PNG.
             
+            if (icon_content == null || icon_content.length == 0)
+                return;
+            
+            Geary.Memory.ByteBuffer buffer = new Geary.Memory.ByteBuffer.take((owned) icon_content,
+                icon_content.length);
+            
             // Then set the source to a data url.
             WebKit.DOM.HTMLImageElement img = Util.DOM.select(get_dom_document(), selector)
                 as WebKit.DOM.HTMLImageElement;
-            set_data_url(img, "image/png", icon_content);
+            img.set_attribute("src", assemble_data_uri("image/png", buffer));
         } catch (Error error) {
             warning("Failed to load icon '%s': %s", icon_name, error.message);
         }
     }
     
-    public void set_image_src(WebKit.DOM.HTMLImageElement img, string mime_type, string filename,
+    public void set_attachment_src(WebKit.DOM.HTMLImageElement img, string mime_type, string filename,
         int maxwidth, int maxheight = -1) {
         if( maxheight == -1 ){
             maxheight = maxwidth;
@@ -248,17 +254,14 @@ public class ConversationWebView : WebKit.WebView {
             }
             
             // Then set the source to a data url.
-            set_data_url(img, icon_mime_type, content);
+            Geary.Memory.Buffer buffer = new Geary.Memory.ByteBuffer.take((owned) content,
+                content.length);
+            img.set_attribute("src", assemble_data_uri(icon_mime_type, buffer));
         } catch (Error error) {
             warning("Failed to load image '%s': %s", filename, error.message);
         }
     }
     
-    public void set_data_url(WebKit.DOM.HTMLImageElement img, string mime_type, uint8[] content)
-        throws Error {
-        img.set_attribute("src", "data:%s;base64,%s".printf(mime_type, Base64.encode(content)));
-    }
-    
     private bool on_navigation_policy_decision_requested(WebKit.WebFrame frame,
         WebKit.NetworkRequest request, WebKit.WebNavigationAction navigation_action,
         WebKit.WebPolicyDecision policy_decision) {

src/engine/rfc822/rfc822-message.vala

@@ -5,6 +5,13 @@
  */
 
 public class Geary.RFC822.Message : BaseObject {
+    /**
+     * This delegate is an optional parameter to the body constructers that allows callers
+     * to process arbitrary non-text, inline MIME parts.
+     */
+    public delegate string? InlinePartReplacer(string filename, string mimetype,
+        Geary.Memory.Buffer buffer);
+    
     private const string DEFAULT_ENCODING = "UTF8";
     
     private const string HEADER_IN_REPLY_TO = "In-Reply-To";
@@ -419,13 +426,6 @@ public class Geary.RFC822.Message : BaseObject {
         return message_to_memory_buffer(true, dotstuffed);
     }
     
-    /**
-     * This delegate is an optional parameter to the body constructers that allows callers
-     * to process arbitrary non-text, inline MIME parts.
-     */
-    public delegate string? InlinePartReplacer(string filename, string mimetype,
-        Geary.Memory.Buffer buffer);
-        
     /**
      * This method is the main utility method used by the other body constructors. It calls itself
      * recursively via the last argument ("node").
@@ -605,13 +605,20 @@ public class Geary.RFC822.Message : BaseObject {
     
     public Memory.Buffer get_content_by_mime_id(string mime_id) throws RFC822Error {
         GMime.Part? part = find_mime_part_by_mime_id(message.get_mime_part(), mime_id);
-        if (part == null) {
+        if (part == null)
-            throw new RFC822Error.NOT_FOUND("Could not find a MIME part with content-id %s",
+            throw new RFC822Error.NOT_FOUND("Could not find a MIME part with Content-ID %s", mime_id);
-                mime_id);
+        
-        }
         return mime_part_to_memory_buffer(part);
     }
-
+    
+    public string? get_content_filename_by_mime_id(string mime_id) throws RFC822Error {
+        GMime.Part? part = find_mime_part_by_mime_id(message.get_mime_part(), mime_id);
+        if (part == null)
+            throw new RFC822Error.NOT_FOUND("Could not find a MIME part with Content-ID %s", mime_id);
+        
+        return part.get_filename();
+    }
+    
     private GMime.Part? find_mime_part_by_mime_id(GMime.Object root, string mime_id) {
         // If this is a multipart container, check each of its children.
         if (root is GMime.Multipart) {

theming/message-viewer.css

@@ -203,7 +203,7 @@ body:not(.nohide) .email.hide .header_container .avatar {
     margin-right: -0.67em;
 }
 
-.email .replaced_inline_image {
+.email .data_inline_image {
     max-width: 100%;
     display: block;
     margin-top: 1em;