[evolution] I#906 - composer-plain-text-starts-preformatted is not followed when replying to HTML emails

[Milan Crha <mcrha src gnome org>]

commit 5397b37024134506eb2c7f0d197a12066b7e55a8
Author: Milan Crha <mcrha redhat com>
Date:   Wed May 20 12:29:15 2020 +0200

    I#906 - composer-plain-text-starts-preformatted is not followed when replying to HTML emails
    
    Closes https://gitlab.gnome.org/GNOME/evolution/-/issues/906

 src/mail/e-mail-notes.c                 | 25 ++++++++++++++-----------
 src/modules/mail/e-mail-shell-backend.c | 24 ++++++++++++++----------
 2 files changed, 28 insertions(+), 21 deletions(-)
---
diff --git a/src/mail/e-mail-notes.c b/src/mail/e-mail-notes.c
index d99e4b960e..fa192cd6e6 100644
--- a/src/mail/e-mail-notes.c
+++ b/src/mail/e-mail-notes.c
@@ -968,16 +968,20 @@ e_mail_notes_editor_init (EMailNotesEditor *notes_editor)
 {
 }
 
-static gboolean
-set_preformatted_block_format_on_idle_cb (gpointer user_data)
+static void
+set_preformatted_block_format_on_load_finished_cb (EContentEditor *cnt_editor,
+                                                  gpointer user_data)
 {
-       EContentEditor *cnt_editor = user_data;
-
-       g_return_val_if_fail (E_IS_CONTENT_EDITOR (cnt_editor), FALSE);
+       g_return_if_fail (E_IS_CONTENT_EDITOR (cnt_editor));
 
-       e_content_editor_set_block_format (cnt_editor, E_CONTENT_EDITOR_BLOCK_FORMAT_PRE);
+       if (!e_content_editor_get_html_mode (cnt_editor)) {
+               e_content_editor_set_block_format (cnt_editor, E_CONTENT_EDITOR_BLOCK_FORMAT_PRE);
+               e_content_editor_set_changed (cnt_editor, FALSE);
+               e_content_editor_clear_undo_redo_history (cnt_editor);
+       }
 
-       return FALSE;
+       g_signal_handlers_disconnect_by_func (cnt_editor,
+               G_CALLBACK (set_preformatted_block_format_on_load_finished_cb), NULL);
 }
 
 static EMailNotesEditor *
@@ -1133,10 +1137,9 @@ e_mail_notes_editor_new_with_editor (EHTMLEditor *html_editor,
 
        settings = e_util_ref_settings ("org.gnome.evolution.mail");
        e_content_editor_set_html_mode (cnt_editor, g_settings_get_boolean (settings, "composer-send-html"));
-       if (!g_settings_get_boolean (settings, "composer-send-html") &&
-           g_settings_get_boolean (settings, "composer-plain-text-starts-preformatted")) {
-               g_idle_add_full (G_PRIORITY_LOW, set_preformatted_block_format_on_idle_cb,
-                       g_object_ref (cnt_editor), g_object_unref);
+       if (g_settings_get_boolean (settings, "composer-plain-text-starts-preformatted")) {
+               g_signal_connect (cnt_editor, "load-finished",
+                       G_CALLBACK (set_preformatted_block_format_on_load_finished_cb), NULL);
        }
        g_object_unref (settings);
 
diff --git a/src/modules/mail/e-mail-shell-backend.c b/src/modules/mail/e-mail-shell-backend.c
index 277e59b215..b1c756bd67 100644
--- a/src/modules/mail/e-mail-shell-backend.c
+++ b/src/modules/mail/e-mail-shell-backend.c
@@ -518,16 +518,20 @@ mail_shell_backend_window_weak_notify_cb (EShell *shell,
                where_the_object_was);
 }
 
-static gboolean
-set_preformatted_block_format_on_idle_cb (gpointer user_data)
+static void
+set_preformatted_block_format_on_load_finished_cb (EContentEditor *cnt_editor,
+                                                  gpointer user_data)
 {
-       EContentEditor *cnt_editor = user_data;
+       g_return_if_fail (E_IS_CONTENT_EDITOR (cnt_editor));
 
-       g_return_val_if_fail (E_IS_CONTENT_EDITOR (cnt_editor), FALSE);
-
-       e_content_editor_set_block_format (cnt_editor, E_CONTENT_EDITOR_BLOCK_FORMAT_PRE);
+       if (!e_content_editor_get_html_mode (cnt_editor)) {
+               e_content_editor_set_block_format (cnt_editor, E_CONTENT_EDITOR_BLOCK_FORMAT_PRE);
+               e_content_editor_set_changed (cnt_editor, FALSE);
+               e_content_editor_clear_undo_redo_history (cnt_editor);
+       }
 
-       return FALSE;
+       g_signal_handlers_disconnect_by_func (cnt_editor,
+               G_CALLBACK (set_preformatted_block_format_on_load_finished_cb), NULL);
 }
 
 static void
@@ -568,9 +572,9 @@ mail_shell_backend_window_added_cb (GtkApplication *application,
 
                e_content_editor_set_html_mode (cnt_editor, use_html);
 
-               if (!use_html && use_preformatted) {
-                       g_idle_add_full (G_PRIORITY_LOW, set_preformatted_block_format_on_idle_cb,
-                               g_object_ref (cnt_editor), g_object_unref);
+               if (use_preformatted) {
+                       g_signal_connect (cnt_editor, "load-finished",
+                               G_CALLBACK (set_preformatted_block_format_on_load_finished_cb), NULL);
                }
        }