[evolution] Have a single function to convert markdown into HTML

[Milan Crha <mcrha src gnome org>]

commit cb6aa4eb184348ae8580f6c0bd2ffd5ea3b26b2b
Author: Milan Crha <mcrha redhat com>
Date:   Fri Jan 28 09:28:11 2022 +0100

    Have a single function to convert markdown into HTML
    
    To have a single place for any tweaks on the generated HTML.

 src/e-util/e-markdown-editor.c                 | 43 +++++++++++++++++++++++---
 src/e-util/e-markdown-editor.h                 |  3 ++
 src/em-format/e-mail-formatter-text-markdown.c |  7 ++---
 3 files changed, 45 insertions(+), 8 deletions(-)
---
diff --git a/src/e-util/e-markdown-editor.c b/src/e-util/e-markdown-editor.c
index 3325ea6395..dfefde101a 100644
--- a/src/e-util/e-markdown-editor.c
+++ b/src/e-util/e-markdown-editor.c
@@ -562,21 +562,56 @@ gchar *
 e_markdown_editor_dup_html (EMarkdownEditor *self)
 {
        #ifdef HAVE_MARKDOWN
-       GString *html;
-       gchar *text, *converted;
+       gchar *text, *html;
        #endif
 
        g_return_val_if_fail (E_IS_MARKDOWN_EDITOR (self), NULL);
 
        #ifdef HAVE_MARKDOWN
        text = e_markdown_editor_dup_text (self);
-       converted = cmark_markdown_to_html (text ? text : "", text ? strlen (text) : 0,
+       html = e_markdown_util_text_to_html (text, -1);
+
+       g_free (text);
+
+       return html;
+       #else
+       return NULL;
+       #endif
+}
+
+/**
+ * e_markdown_util_text_to_html:
+ * @plain_text: plain text with markdown to convert to HTML
+ * @length: length of the @plain_text, or -1 when it's nul-terminated
+ *
+ * Convert @plain_text, possibly with markdown, into the HTML.
+ *
+ * Note: The function can return %NULL when was not built
+ *    with the markdown support.
+ *
+ * Returns: (transfer full) (nullable): text converted into HTML,
+ *    or %NULL, when was not built with the markdown support.
+ *    Free the string with g_free(), when no longer needed.
+ *
+ * Since: 3.44
+ **/
+gchar *
+e_markdown_util_text_to_html (const gchar *plain_text,
+                             gssize length)
+{
+       #ifdef HAVE_MARKDOWN
+       GString *html;
+       gchar *converted;
+
+       if (length == -1)
+               length = plain_text ? strlen (plain_text) : 0;
+
+       converted = cmark_markdown_to_html (plain_text ? plain_text : "", length,
                CMARK_OPT_VALIDATE_UTF8 | CMARK_OPT_UNSAFE);
 
        html = e_str_replace_string (converted, "<blockquote>", "<blockquote type=\"cite\">");
 
        g_free (converted);
-       g_free (text);
 
        return g_string_free (html, FALSE);
        #else
diff --git a/src/e-util/e-markdown-editor.h b/src/e-util/e-markdown-editor.h
index bdc429c8b9..4369e7c25e 100644
--- a/src/e-util/e-markdown-editor.h
+++ b/src/e-util/e-markdown-editor.h
@@ -52,6 +52,9 @@ GtkWidget *   e_markdown_editor_new                   (void);
 gchar *                e_markdown_editor_dup_text              (EMarkdownEditor *self);
 gchar *                e_markdown_editor_dup_html              (EMarkdownEditor *self);
 
+gchar *                e_markdown_util_text_to_html            (const gchar *plain_text,
+                                                        gssize length);
+
 G_END_DECLS
 
 #endif /* E_MARKDOWN_EDITOR_H */
diff --git a/src/em-format/e-mail-formatter-text-markdown.c b/src/em-format/e-mail-formatter-text-markdown.c
index c73b90ecca..1d0fb906dc 100644
--- a/src/em-format/e-mail-formatter-text-markdown.c
+++ b/src/em-format/e-mail-formatter-text-markdown.c
@@ -15,7 +15,6 @@
 
 #include "evolution-config.h"
 
-#include <cmark.h>
 #include <glib/gi18n-lib.h>
 
 #include <e-util/e-util.h>
@@ -66,9 +65,9 @@ emfe_text_markdown_format (EMailFormatterExtension *extension,
                e_mail_formatter_format_text (formatter, part, output_stream, cancellable);
                g_output_stream_flush (output_stream, cancellable, NULL);
 
-               html = cmark_markdown_to_html ((const gchar *) g_memory_output_stream_get_data 
(G_MEMORY_OUTPUT_STREAM (output_stream)),
-                                              g_memory_output_stream_get_data_size (G_MEMORY_OUTPUT_STREAM 
(output_stream)),
-                                              CMARK_OPT_VALIDATE_UTF8 | CMARK_OPT_UNSAFE);
+               html = e_markdown_util_text_to_html ((const gchar *) g_memory_output_stream_get_data 
(G_MEMORY_OUTPUT_STREAM (output_stream)),
+                       g_memory_output_stream_get_data_size (G_MEMORY_OUTPUT_STREAM (output_stream)));
+
                g_object_unref (output_stream);
                g_object_unref (mime_part);