Add a helper function to copy over configuration and use it. Bug 741883

The function is called just before the engine gets started, so
hopefully just before any files are read by Geary.

po/POTFILES.in

@@ -84,6 +84,7 @@ src/client/util/util-files.vala
 src/client/util/util-gravatar.vala
 src/client/util/util-gtk.vala
 src/client/util/util-international.vala
+src/client/util/util-migrate.vala
 src/client/util/util-random.vala
 src/client/util/util-webkit.vala
 src/console/main.vala

src/CMakeLists.txt

@@ -403,6 +403,7 @@ client/util/util-gtk.vala
 client/util/util-international.vala
 client/util/util-random.vala
 client/util/util-webkit.vala
+client/util/util-migrate.vala
 )
 
 set(CONSOLE_SRC

src/client/application/geary-controller.vala

@@ -245,7 +245,15 @@ public class GearyController : Geary.BaseObject {
         
         // initialize revokable
         save_revokable(null, null);
-        
+
+        // Migrate configuration if necessary.
+        try {
+            Migrate.xdg_config_dir(GearyApplication.instance.get_user_data_directory(),
+                GearyApplication.instance.get_user_config_directory());
+        } catch (Error e) {
+            error("Error migrating configuration directories: %s", e.message);
+        }
+
         // Start Geary.
         try {
             yield Geary.Engine.instance.open_async(GearyApplication.instance.get_user_data_directory(), 

src/client/util/util-migrate.vala

@@ -0,0 +1,107 @@
+/* Copyright 2016 Software Freedom Conservancy Inc.
+ *
+ * This software is licensed under the GNU Lesser General Public License
+ * (version 2.1 or later).  See the COPYING file in this distribution.
+ */
+
+namespace Migrate {
+    private const string GROUP = "AccountInformation";
+    private const string PRIMARY_EMAIL_KEY = "primary_email";
+    private const string SETTINGS_FILENAME = Geary.AccountInformation.SETTINGS_FILENAME;
+    private const string MIGRATED_FILENAME = ".config_migrated";
+
+    /**
+     * Migrates geary.ini to the XDG configuration directory with the account's email address
+     *
+     * This function iterates through all the account directories in $XDG_DATA_DIR and copies over
+     * geary.ini to ~/.config/geary/<account>/geary.ini. Note that it leaves the
+     * original file untouched.
+     * It also appends a "primary_email" key to the new configuration file to reliaby keep
+     * track of the user's email address.
+     */
+    public static void xdg_config_dir(File user_data_dir, File user_config_dir) throws Error {
+        File new_config_dir;
+        File old_data_dir;
+        File new_config_file;
+        File old_config_file;
+
+        // Create ~/.config/geary
+        try {
+            user_config_dir.make_directory_with_parents();
+        } catch (Error err) {
+            // The user may have already created the directory, so don't throw EXISTS.
+            if (!(err is IOError.EXISTS))
+                throw err;
+        }
+
+        FileEnumerator enumerator;
+        enumerator = user_data_dir.enumerate_children ("standard::*",
+            FileQueryInfoFlags.NOFOLLOW_SYMLINKS, null);
+
+        FileInfo? info;
+        string email;
+        File is_migrated;
+        while ((info = enumerator.next_file(null)) != null) {
+            if (info.get_file_type() != FileType.DIRECTORY)
+                continue;
+
+            email = info.get_name();
+
+            // Skip the directory if its name is not a valid email address.
+            if (!Geary.RFC822.MailboxAddress.is_valid_address(email))
+                continue;
+
+            old_data_dir = user_data_dir.get_child(email);
+            new_config_dir = user_config_dir.get_child(email);
+
+            // Skip the directory if ~/.local/share/geary/<account>/geary.ini does not exist.
+            old_config_file = old_data_dir.get_child(SETTINGS_FILENAME);
+            if (!old_config_file.query_exists())
+                continue;
+
+            // Skip the directory if ~/.local/share/geary/<account>/.config_migrated exists.
+            is_migrated = old_data_dir.get_child(MIGRATED_FILENAME);
+            if (is_migrated.query_exists())
+                continue;
+
+            if (!new_config_dir.query_exists()) {
+                try {
+                    new_config_dir.make_directory_with_parents();
+                } catch (Error e) {
+                    debug("Cannot make directory, %s", e.message);
+                    continue;
+                }
+            }
+
+            new_config_file = new_config_dir.get_child(SETTINGS_FILENAME);
+            if (new_config_file.query_exists())
+                continue;
+
+            try {
+                old_config_file.copy(new_config_file, FileCopyFlags.NONE);
+            } catch (Error err) {
+                debug("Error copying over to %s", new_config_dir.get_path());
+                continue;
+            }
+            KeyFile key_file = new KeyFile();
+            try {
+                key_file.load_from_file(new_config_file.get_path(), KeyFileFlags.NONE);
+            } catch (Error err) {
+                debug("Error opening %s", new_config_file.get_path());
+                continue;
+            }
+
+            // Write the primary email key in the new config file.
+            key_file.set_value(GROUP, PRIMARY_EMAIL_KEY, email);
+            string data = key_file.to_data();
+            try {
+                new_config_file.replace_contents(data.data, null, false, FileCreateFlags.NONE,
+                null);
+            } catch (Error e) {
+                debug("Error writing email %s to config file", email);
+                continue;
+            }
+            is_migrated.create(FileCreateFlags.PRIVATE);
+        }
+    }
+}