Correctly handle the jpeg quality dialog being cancelled.

Bug: #1322878

Pinta.Core/ImageFormats/JpegFormat.cs

@@ -57,16 +57,16 @@ protected override void DoSave(Pixbuf pb, string fileName, string fileType, Gtk.
 				//Show the user the JPG export compression quality dialog, with the default
 				//value being the one loaded in (or the default value if it was not saved).
 				level = PintaCore.Actions.File.RaiseModifyCompression(level, parent);
+
+				if (level == -1)
+					throw new OperationCanceledException ();
 			}
 
-			if (level != -1)
-			{
-				//Store the "previous" JPG compression quality value (before saving with it).
-				PintaCore.Settings.PutSetting(JpgCompressionQualitySetting, level);
+			//Store the "previous" JPG compression quality value (before saving with it).
+			PintaCore.Settings.PutSetting(JpgCompressionQualitySetting, level);
 
-				//Save the file.
-				pb.SavevUtf8(fileName, fileType, new string[] { "quality", null }, new string[] { level.ToString(), null });
-			}
+			//Save the file.
+			pb.SavevUtf8(fileName, fileType, new string[] { "quality", null }, new string[] { level.ToString(), null });
 		}
 	}
 }

Pinta/Actions/File/SaveDocumentImplementationAction.cs

@@ -155,11 +155,15 @@ private bool SaveFileAs (Document document)
 
 				PintaCore.System.LastDialogDirectory = fcd.CurrentFolder;
 
+				// If saving the file failed or was cancelled, let the user select
+				// a different file type.
+				if (!SaveFile (document, file, format, fcd))
+					continue;
+
 				//The user is saving the Document to a new file, so technically it
 				//hasn't been saved to its associated file in this session.
 				document.HasBeenSavedInSession = false;
 
-				SaveFile (document, file, format, fcd);
 				RecentManager.Default.AddFull (fcd.Uri, PintaCore.System.RecentData);
 				PintaCore.System.ImageFormats.SetDefaultFormat (Path.GetExtension (file));
 
@@ -223,6 +227,8 @@ private bool SaveFile (Document document, string file, FormatDescriptor format,
 				} else {
 					throw e; // Only catch exceptions we know the reason for
 				}
+			} catch (OperationCanceledException) {
+				return false;
 			}
 
 			document.Filename = Path.GetFileName (file);