[evolution] Crash on paste of a vCard into a message composer body

[Milan Crha <mcrha src gnome org>]

commit 960890f1babaed48216fc0e93871dc0fe9683a12
Author: Milan Crha <mcrha redhat com>
Date:   Wed Dec 21 11:36:22 2016 +0100

    Crash on paste of a vCard into a message composer body
    
    This had been reported downstream as:
    https://bugzilla.redhat.com/show_bug.cgi?id=1406510
    
    Copying (right click Copy) a contact from the Contacts page and
    the trying to Paste into the body of a new email message, causes
    a crash in webkit_editor_paste_clipboard_targets_cb().

 src/e-util/e-html-editor-actions.c          |    3 +++
 src/modules/webkit-editor/e-webkit-editor.c |    5 ++++-
 2 files changed, 7 insertions(+), 1 deletions(-)
---
diff --git a/src/e-util/e-html-editor-actions.c b/src/e-util/e-html-editor-actions.c
index f0649e6..9fb9b0f 100644
--- a/src/e-util/e-html-editor-actions.c
+++ b/src/e-util/e-html-editor-actions.c
@@ -555,6 +555,9 @@ clipboard_text_received_for_paste_as_text (GtkClipboard *clipboard,
 {
        EContentEditor *cnt_editor;
 
+       if (!text || !*text)
+               return;
+
        cnt_editor = e_html_editor_get_content_editor (editor);
        e_content_editor_insert_content (
                cnt_editor,
diff --git a/src/modules/webkit-editor/e-webkit-editor.c b/src/modules/webkit-editor/e-webkit-editor.c
index 4dbd878..43cc223 100644
--- a/src/modules/webkit-editor/e-webkit-editor.c
+++ b/src/modules/webkit-editor/e-webkit-editor.c
@@ -5665,6 +5665,7 @@ webkit_editor_paste_clipboard_targets_cb (GtkClipboard *clipboard,
 
                webkit_editor_insert_image (E_CONTENT_EDITOR (wk_editor), uri);
 
+               g_free (content);
                g_free (uri);
 
                return;
@@ -5676,8 +5677,10 @@ webkit_editor_paste_clipboard_targets_cb (GtkClipboard *clipboard,
        /* Prefer plain text over HTML when in the plain text mode, but only
         * when pasting content from outside the editor view. */
 
-       if (!content && !*content)
+       if (!content || !*content) {
+               g_free (content);
                return;
+       }
 
        if (is_html)
                webkit_editor_insert_content (