[geary] Save inline images correctly to disk: Bug #738877

[Jim Nelson <jnelson src gnome org>]

commit e93c784aacf62fe485d6404846dee15dc5122b31
Author: Jim Nelson <jim yorba org>
Date:   Mon Oct 20 17:30:43 2014 -0700

    Save inline images correctly to disk: Bug #738877
    
    Inline images are rotated and scaled when displayed in the
    conversation viewer for speed reasons (as well as to make extremely
    large images manageable for the user to view).  They were converted
    to PNG during this operation.
    
    Saving the image was, in turn, saving the rotated/scaled PNG although
    the filename remained the original name (i.e. .jpg, usually), causing
    issues for other tools who detect image type from the extension.
    
    This patch solves this problem by maintaining the original image
    buffer in memory.  When the user goes to save the image, the original
    buffer is saved, not the rotated and scaled PNG.

 .../conversation-viewer/conversation-viewer.vala   |   86 +++++++++++++-------
 1 files changed, 58 insertions(+), 28 deletions(-)
---
diff --git a/src/client/conversation-viewer/conversation-viewer.vala 
b/src/client/conversation-viewer/conversation-viewer.vala
index ca59430..65f1974 100644
--- a/src/client/conversation-viewer/conversation-viewer.vala
+++ b/src/client/conversation-viewer/conversation-viewer.vala
@@ -82,6 +82,20 @@ public class ConversationViewer : Gtk.Box {
         }
     }
     
+    // Internal class to associate inline image buffers (replaced by rotated scaled versions of
+    // them) so they can be saved intact if the user requires it
+    private class ReplacedImage : Geary.BaseObject {
+        public string id;
+        public string filename;
+        public Geary.Memory.Buffer buffer;
+        
+        public ReplacedImage(int replaced_number, string filename, Geary.Memory.Buffer buffer) {
+            id = "%X".printf(replaced_number);
+            this.filename = filename;
+            this.buffer = buffer;
+        }
+    }
+    
     // Fired when the user clicks a link.
     public signal void link_selected(string link);
     
@@ -152,6 +166,8 @@ public class ConversationViewer : Gtk.Box {
     private DisplayMode display_mode = DisplayMode.NONE;
     private uint select_conversation_timeout_id = 0;
     private Gee.HashSet<string> inlined_content_ids = new Gee.HashSet<string>();
+    private int next_replaced_buffer_number = 0;
+    private Gee.HashMap<string, ReplacedImage> replaced_images = new Gee.HashMap<string, ReplacedImage>();
     
     public ConversationViewer() {
         Object(orientation: Gtk.Orientation.VERTICAL, spacing: 0);
@@ -282,6 +298,7 @@ public class ConversationViewer : Gtk.Box {
         email_to_element.clear();
         messages.clear();
         inlined_content_ids.clear();
+        replaced_images.clear();
         
         current_account_information = account_information;
     }
@@ -647,7 +664,7 @@ 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, "." + DATA_IMAGE_CLASS, "contextmenu", (Callback) on_data_image_menu, this);
+        bind_event(web_view, "." + DATA_IMAGE_CLASS, "contextmenu", (Callback) on_data_image_menu_handler, 
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);
@@ -800,7 +817,7 @@ public class ConversationViewer : Gtk.Box {
         return false;
     }
     
-    private static string? inline_image_replacer(string filename, Geary.Mime.ContentType? content_type,
+    private string? inline_image_replacer(string filename, Geary.Mime.ContentType? content_type,
         Geary.Mime.ContentDisposition? disposition, string? content_id, Geary.Memory.Buffer buffer) {
         if (content_type == null || !is_content_type_supported_inline(content_type)) {
             debug("Not displaying %s inline: unsupported Content-Type", content_type.to_string());
@@ -814,6 +831,7 @@ public class ConversationViewer : Gtk.Box {
         // have the doucment set up to reduce the size of the image to fit in the viewport, and a
         // scaled load-and-deode is always faster than load followed by scale.
         Geary.Memory.Buffer rotated_image = buffer;
+        string mime_type = content_type.get_mime_type();
         try {
             Gdk.PixbufLoader loader = new Gdk.PixbufLoader();
             loader.size_prepared.connect(on_inline_image_size_prepared);
@@ -838,6 +856,7 @@ public class ConversationViewer : Gtk.Box {
                 // Save length before transferring ownership (which frees the array)
                 int image_length = image_data.length;
                 rotated_image = new Geary.Memory.ByteBuffer.take((owned) image_data, image_length);
+                mime_type = "image/png";
             }
         } catch (Error err) {
             debug("Unable to load and rotate image %s for display: %s", filename, err.message);
@@ -845,9 +864,19 @@ public class ConversationViewer : Gtk.Box {
         
         string? escaped_content_id = (content_id != null) ? Geary.HTML.escape_markup(content_id) : null;
         
-        return "<img alt=\"%s\" class=\"%s %s\" src=\"%s\" %s />".printf(
-            filename, DATA_IMAGE_CLASS, REPLACED_IMAGE_CLASS,
-            assemble_data_uri(content_type.get_mime_type(), rotated_image),
+        // Store the original buffer and its filename in a local map so they can be recalled later
+        // (if the user wants to save it) ... note that Content-ID is optional and there's no
+        // guarantee that filename will be unique, even in the same message, so need to generate
+        // a unique identifier for each object
+        ReplacedImage replaced_image = new ReplacedImage(next_replaced_buffer_number++, filename,
+            buffer);
+        replaced_images.set(replaced_image.id, replaced_image);
+        
+        return "<img alt=\"%s\" class=\"%s %s\" src=\"%s\" replaced-id=\"%s\" %s />".printf(
+            Geary.HTML.escape_markup(filename),
+            DATA_IMAGE_CLASS, REPLACED_IMAGE_CLASS,
+            assemble_data_uri(mime_type, rotated_image),
+            Geary.HTML.escape_markup(replaced_image.id),
             escaped_content_id != null ? @"cid=\"$escaped_content_id\"" : "");
     }
     
@@ -1530,18 +1559,36 @@ public class ConversationViewer : Gtk.Box {
             conversation_viewer.show_attachment_menu(email, attachment);
     }
     
-    private static void on_data_image_menu(WebKit.DOM.Element element, WebKit.DOM.Event event,
+    private static void on_data_image_menu_handler(WebKit.DOM.Element element, WebKit.DOM.Event event,
         ConversationViewer conversation_viewer) {
+        conversation_viewer.on_data_image_menu(element, event);
+    }
+    
+    private void on_data_image_menu(WebKit.DOM.Element element, WebKit.DOM.Event event) {
         event.stop_propagation();
         
-        Geary.Memory.Buffer? buffer;
-        if (!dissasemble_data_uri(element.get_attribute("src"), out buffer))
+        string? replaced_id = element.get_attribute("replaced-id");
+        if (Geary.String.is_empty(replaced_id))
+            return;
+        
+        ReplacedImage? replaced_image = replaced_images.get(replaced_id);
+        if (replaced_image == null)
             return;
         
-        string? filename = element.get_attribute("alt");
+        image_menu = new Gtk.Menu();
+        image_menu.selection_done.connect(() => {
+            image_menu = null;
+         });
+        
+        Gtk.MenuItem save_image_item = new Gtk.MenuItem.with_mnemonic(_("_Save Image As..."));
+        save_image_item.activate.connect(() => {
+            save_buffer_to_file(replaced_image.filename, replaced_image.buffer);
+        });
+        image_menu.append(save_image_item);
         
-        if (buffer != null && buffer.size > 0)
-            conversation_viewer.show_replaced_image_menu(filename, buffer);
+        image_menu.show_all();
+        
+        image_menu.popup(null, null, null, 0, Gtk.get_current_event_time());
     }
     
     private void on_message_menu_selection_done() {
@@ -1650,23 +1697,6 @@ public class ConversationViewer : Gtk.Box {
         return menu;
     }
     
-    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;
-         });
-        
-        Gtk.MenuItem save_image_item = new Gtk.MenuItem.with_mnemonic(_("_Save Image As..."));
-        save_image_item.activate.connect(() => {
-            save_buffer_to_file(filename, buffer);
-        });
-        image_menu.append(save_image_item);
-        
-        image_menu.show_all();
-        
-        image_menu.popup(null, null, null, 0, Gtk.get_current_event_time());
-    }
-    
     private void show_message_menu(Geary.Email email) {
         message_menu = build_message_menu(email);
         message_menu.show_all();