[evolution] Fix a memory leak in e_editor_dom_process_content_to_plain_text_for_exporting()

[Milan Crha <mcrha src gnome org>]

commit 49a755aa49c5b7a25369499a7259fac1c4a0aa89
Author: Milan Crha <mcrha redhat com>
Date:   Fri Mar 2 12:37:01 2018 +0100

    Fix a memory leak in e_editor_dom_process_content_to_plain_text_for_exporting()
    
    And simplify two functions, which also use g_string_free().

 .../web-extension/e-editor-dom-functions.c         |   16 +++++-----------
 1 files changed, 5 insertions(+), 11 deletions(-)
---
diff --git a/src/modules/webkit-editor/web-extension/e-editor-dom-functions.c 
b/src/modules/webkit-editor/web-extension/e-editor-dom-functions.c
index 1932b40..961a1f6 100644
--- a/src/modules/webkit-editor/web-extension/e-editor-dom-functions.c
+++ b/src/modules/webkit-editor/web-extension/e-editor-dom-functions.c
@@ -6959,7 +6959,6 @@ get_alpha_value (gint value,
                  gboolean lower)
 {
        GString *str;
-       gchar *rv;
        gint add = lower ? 'a' : 'A';
 
        str = g_string_new (". ");
@@ -6969,10 +6968,7 @@ get_alpha_value (gint value,
                value = (value - 1) / 26;
        } while (value);
 
-       rv = str->str;
-       g_string_free (str, FALSE);
-
-       return rv;
+       return g_string_free (str, FALSE);
 }
 
 /* Taken from GtkHTML */
@@ -6982,7 +6978,6 @@ get_roman_value (gint value,
 {
        GString *str;
        const gchar *base = "IVXLCDM";
-       gchar *rv;
        gint b, r, add = lower ? 'a' - 'A' : 0;
 
        if (value > 3999)
@@ -7012,10 +7007,7 @@ get_roman_value (gint value,
                }
        }
 
-       rv = str->str;
-       g_string_free (str, FALSE);
-
-       return rv;
+       return g_string_free (str, FALSE);
 }
 
 static void
@@ -8352,13 +8344,15 @@ e_editor_dom_process_content_to_plain_text_for_exporting (EEditorPage *editor_pa
                                list_pre = webkit_dom_document_create_element (document, "pre", NULL);
                                webkit_dom_html_element_set_inner_text (
                                        WEBKIT_DOM_HTML_ELEMENT (list_pre),
-                                       g_string_free (list_plain_text, FALSE),
+                                       list_plain_text->str,
                                        NULL);
                                webkit_dom_node_replace_child (
                                        WEBKIT_DOM_NODE (wrapper),
                                        WEBKIT_DOM_NODE (list_pre),
                                        item,
                                        NULL);
+
+                               g_string_free (list_plain_text, TRUE);
                        }
                        g_clear_object (&list);