[evolution/gnome-41] I#1571 - Broken font settings can break message display

[Milan Crha <mcrha src gnome org>]

commit 3a4e0c8832e828c8908c8082e6e9684fe292e8f1
Author: Milan Crha <mcrha redhat com>
Date:   Tue Dec 7 12:30:55 2021 +0100

    I#1571 - Broken font settings can break message display
    
    Closes https://gitlab.gnome.org/GNOME/evolution/-/issues/1571

 src/e-util/e-web-view.c                     | 22 ++++++++++++++++++++--
 src/modules/webkit-editor/e-webkit-editor.c | 20 ++++++++++++++++----
 2 files changed, 36 insertions(+), 6 deletions(-)
---
diff --git a/src/e-util/e-web-view.c b/src/e-util/e-web-view.c
index 1115ab8e9b..9ab13b69cc 100644
--- a/src/e-util/e-web-view.c
+++ b/src/e-util/e-web-view.c
@@ -3327,7 +3327,7 @@ e_web_view_update_fonts_settings (GSettings *font_settings,
                        "monospace-font-name");
 
                ms = pango_font_description_from_string (
-                       (font != NULL) ? font : "monospace 10");
+                       (font && *font) ? font : "monospace 10");
 
                clean_ms = TRUE;
 
@@ -3335,6 +3335,15 @@ e_web_view_update_fonts_settings (GSettings *font_settings,
        } else
                ms = ms_font;
 
+       if (!pango_font_description_get_family (ms) ||
+           !pango_font_description_get_size (ms)) {
+               if (clean_ms)
+                       pango_font_description_free (ms);
+
+               clean_ms = TRUE;
+               ms = pango_font_description_from_string ("monospace 10");
+       }
+
        if (!vw_font) {
                gchar *font;
 
@@ -3343,7 +3352,7 @@ e_web_view_update_fonts_settings (GSettings *font_settings,
                        "font-name");
 
                vw = pango_font_description_from_string (
-                       (font != NULL) ? font : "serif 10");
+                       (font && *font) ? font : "serif 10");
 
                clean_vw = TRUE;
 
@@ -3351,6 +3360,15 @@ e_web_view_update_fonts_settings (GSettings *font_settings,
        } else
                vw = vw_font;
 
+       if (!pango_font_description_get_family (vw) ||
+           !pango_font_description_get_size (vw)) {
+               if (clean_vw)
+                       pango_font_description_free (vw);
+
+               clean_vw = TRUE;
+               vw = pango_font_description_from_string ("serif 10");
+       }
+
        stylesheet = g_string_new ("");
        g_ascii_dtostr (fsbuff, G_ASCII_DTOSTR_BUF_SIZE,
                ((gdouble) pango_font_description_get_size (vw)) / PANGO_SCALE);
diff --git a/src/modules/webkit-editor/e-webkit-editor.c b/src/modules/webkit-editor/e-webkit-editor.c
index 4312d7f739..1042cc1bcd 100644
--- a/src/modules/webkit-editor/e-webkit-editor.c
+++ b/src/modules/webkit-editor/e-webkit-editor.c
@@ -1179,25 +1179,31 @@ webkit_editor_update_styles (EContentEditor *editor)
        if (use_custom_font) {
                font = g_settings_get_string (
                        wk_editor->priv->mail_settings, "monospace-font");
-               ms = pango_font_description_from_string (font ? font : "monospace 10");
+               ms = pango_font_description_from_string (font && *font ? font : "monospace 10");
                g_free (font);
        } else {
                font = g_settings_get_string (
                        wk_editor->priv->font_settings, "monospace-font-name");
-               ms = pango_font_description_from_string (font ? font : "monospace 10");
+               ms = pango_font_description_from_string (font && *font ? font : "monospace 10");
                g_free (font);
        }
 
+       if (!pango_font_description_get_family (ms) ||
+           !pango_font_description_get_size (ms)) {
+               pango_font_description_free (ms);
+               ms = pango_font_description_from_string ("monospace 10");
+       }
+
        if (wk_editor->priv->html_mode) {
                if (use_custom_font) {
                        font = g_settings_get_string (
                                wk_editor->priv->mail_settings, "variable-width-font");
-                       vw = pango_font_description_from_string (font ? font : "serif 10");
+                       vw = pango_font_description_from_string (font && *font ? font : "serif 10");
                        g_free (font);
                } else {
                        font = g_settings_get_string (
                                wk_editor->priv->font_settings, "font-name");
-                       vw = pango_font_description_from_string (font ? font : "serif 10");
+                       vw = pango_font_description_from_string (font && *font ? font : "serif 10");
                        g_free (font);
                }
        } else {
@@ -1205,6 +1211,12 @@ webkit_editor_update_styles (EContentEditor *editor)
                vw = pango_font_description_copy (ms);
        }
 
+       if (!pango_font_description_get_family (vw) ||
+           !pango_font_description_get_size (vw)) {
+               pango_font_description_free (vw);
+               vw = pango_font_description_from_string ("serif 10");
+       }
+
        stylesheet = g_string_new ("");
        g_ascii_dtostr (fsbuff, G_ASCII_DTOSTR_BUF_SIZE,
                ((gdouble) pango_font_description_get_size (vw)) / PANGO_SCALE);