[geary/wip/conversation-polish: 7/22] Retry fetching remote email body when loading but command times out

[Michael Gratton <mjog src gnome org>]

commit b9942cac9401a3c7c084944ad83b06be6de7f029
Author: Michael Gratton <mike vee net>
Date:   Thu Jan 24 09:15:16 2019 +1100

    Retry fetching remote email body when loading but command times out

 .../conversation-viewer/conversation-email.vala    | 55 +++++++++++++++-------
 1 file changed, 38 insertions(+), 17 deletions(-)
---
diff --git a/src/client/conversation-viewer/conversation-email.vala 
b/src/client/conversation-viewer/conversation-email.vala
index 297c382f..b354d233 100644
--- a/src/client/conversation-viewer/conversation-email.vala
+++ b/src/client/conversation-viewer/conversation-email.vala
@@ -596,7 +596,7 @@ public class ConversationEmail : Gtk.Box, Geary.BaseInterface {
             } catch (Geary.EngineError.INCOMPLETE_MESSAGE err) {
                 // Don't have the complete message at the moment, so
                 // download it in the background.
-                this.fetch_body_remote.begin();
+                this.fetch_remote_body.begin();
             }
             this.body_loading_timeout.reset();
         }
@@ -736,27 +736,48 @@ public class ConversationEmail : Gtk.Box, Geary.BaseInterface {
             });
     }
 
-    private async void fetch_body_remote()
+    private async void fetch_remote_body()
         throws GLib.Error {
+        // Retry the remote fetch once if the first time fails, so if
+        // the connection has timed out we will establish a new one.
+        const int MAX_RETRIES = 2;
+
         // XXX Need proper progress reporting here, rather than just
         // doing a pulse
         this.primary_message.start_progress_pulse();
+
+        int retries = 0;
         Geary.Email? loaded = null;
-        try {
-            loaded = yield this.email_store.fetch_email_async(
-                this.email.id,
-                REQUIRED_FOR_LOAD,
-                FORCE_UPDATE,
-                this.load_cancellable
-            );
-        } catch (GLib.IOError.CANCELLED err) {
-            // Don't stop message progress pulse here since if
-            // cancelled, this could be well after the widgets have
-            // been removed and destroyed
-        } catch (GLib.Error err) {
-            // XXX Notify user of a problem here
-            debug("Remote message download failed: %s", err.message);
-            this.primary_message.stop_progress_pulse();
+        while (retries < MAX_RETRIES) {
+            retries++;
+            try {
+                loaded = yield this.email_store.fetch_email_async(
+                    this.email.id,
+                    REQUIRED_FOR_LOAD,
+                    FORCE_UPDATE,
+                    this.load_cancellable
+                );
+            } catch (GLib.IOError.CANCELLED err) {
+                // Don't stop message progress pulse here since if
+                // cancelled, this could be well after the widgets have
+                // been removed and destroyed
+                throw err;
+            } catch (Geary.ImapError.TIMED_OUT err) {
+                if (retries < MAX_RETRIES) {
+                    debug("Remote message download timed out, retrying: %s",
+                          err.message);
+                } else {
+                    debug("Remote message download timed out, giving up %s",
+                          err.message);
+                    this.primary_message.stop_progress_pulse();
+                    throw err;
+                }
+            } catch (GLib.Error err) {
+                // XXX Notify user of a problem here
+                debug("Remote message download failed: %s", err.message);
+                this.primary_message.stop_progress_pulse();
+                throw err;
+            }
         }
 
         if (loaded != null) {