[evolution] I#1835 - Mail: Preview uses wrong colors for HTML mail with dark theme

[Milan Crha <mcrha src gnome org>]

commit ac15857f14eecd83a3a1950588a2f1edb9cb70de
Author: Milan Crha <mcrha redhat com>
Date:   Fri Mar 18 09:45:20 2022 +0100

    I#1835 - Mail: Preview uses wrong colors for HTML mail with dark theme
    
    Closes https://gitlab.gnome.org/GNOME/evolution/-/issues/1835

 data/webkit/e-web-view.js                  | 12 ++++++++++--
 src/em-format/e-mail-formatter-text-html.c |  2 +-
 2 files changed, 11 insertions(+), 3 deletions(-)
---
diff --git a/data/webkit/e-web-view.js b/data/webkit/e-web-view.js
index 7f47fe4b26..a8f99c4668 100644
--- a/data/webkit/e-web-view.js
+++ b/data/webkit/e-web-view.js
@@ -695,8 +695,16 @@ Evo.initialize = function(elem)
 
        if (doc.documentElement.style.getPropertyValue("color") == "" ||
            doc.documentElement.style.getPropertyValue("color") == "text") {
-               doc.documentElement.style.setProperty("color", "inherit");
-               doc.documentElement.style.setProperty("background-color", "inherit");
+               if (doc.defaultView && doc.defaultView.frameElement && 
!doc.defaultView.frameElement.hasAttribute("x-e-unset-colors") &&
+                   doc.defaultView.frameElement.ownerDocument &&
+                   doc.defaultView.frameElement.ownerDocument.defaultView &&
+                   doc.defaultView.frameElement.ownerDocument.defaultView.window) {
+                       var style = 
doc.defaultView.frameElement.ownerDocument.defaultView.window.getComputedStyle(doc.defaultView.frameElement);
+                       if (style) {
+                               doc.documentElement.style.setProperty("color", style.color);
+                               doc.documentElement.style.setProperty("background-color", 
style.backgroundColor);
+                       }
+               }
        }
 
        elems = doc.querySelectorAll("input, textarea, select, button, label");
diff --git a/src/em-format/e-mail-formatter-text-html.c b/src/em-format/e-mail-formatter-text-html.c
index 708c29a5e4..8a938212ff 100644
--- a/src/em-format/e-mail-formatter-text-html.c
+++ b/src/em-format/e-mail-formatter-text-html.c
@@ -369,7 +369,7 @@ emfe_text_html_format (EMailFormatterExtension *extension,
                        e_mail_part_get_id (part),
                        e_mail_part_get_id (part),
                        e_mail_part_get_frame_security_style (part),
-                       g_settings_get_boolean (settings, "preview-unset-html-colors") ? 
"x-e-unset-colors=\"1\"" : "style=\"background-color: #ffffff;\"");
+                       g_settings_get_boolean (settings, "preview-unset-html-colors") ? 
"x-e-unset-colors=\"1\"" : "style=\"background-color:white; color:black;\"");
 
                g_output_stream_write_all (
                        stream, str, strlen (str),