[evolution] Fix a possible memory leak in mail_display_uri_requested_cb()

[Milan Crha <mcrha src gnome org>]

commit acf1095e1531c893c054452af15cb337421a3198
Author: Milan Crha <mcrha redhat com>
Date:   Mon May 28 15:44:21 2018 +0200

    Fix a possible memory leak in mail_display_uri_requested_cb()
    
    Related to https://bugzilla.gnome.org/show_bug.cgi?id=796419

 src/mail/e-mail-display.c | 36 +++++++++++++++++++++++++-----------
 1 file changed, 25 insertions(+), 11 deletions(-)
---
diff --git a/src/mail/e-mail-display.c b/src/mail/e-mail-display.c
index 5a1fd7a04f..4aeabd1aef 100644
--- a/src/mail/e-mail-display.c
+++ b/src/mail/e-mail-display.c
@@ -1703,7 +1703,7 @@ mail_display_uri_requested_cb (EWebView *web_view,
        if (uri_is_http) {
                CamelFolder *folder;
                const gchar *message_uid;
-               gchar *new_uri, *mail_uri, *enc;
+               gchar *new_uri, *mail_uri;
                SoupURI *soup_uri;
                GHashTable *query;
                gboolean can_download_uri;
@@ -1744,14 +1744,29 @@ mail_display_uri_requested_cb (EWebView *web_view,
                mail_uri = e_mail_part_build_uri (
                        folder, message_uid, NULL, NULL);
 
-               if (soup_uri->query)
-                       query = soup_form_decode (soup_uri->query);
-               else
-                       query = g_hash_table_new_full (
-                               g_str_hash, g_str_equal,
-                               g_free, g_free);
-               enc = soup_uri_encode (mail_uri, NULL);
-               g_hash_table_insert (query, g_strdup ("__evo-mail"), enc);
+               query = g_hash_table_new_full (
+                       g_str_hash, g_str_equal,
+                       g_free, g_free);
+
+               if (soup_uri->query) {
+                       GHashTable *uri_query;
+                       GHashTableIter iter;
+                       gpointer key, value;
+
+                       /* It's required to copy the hash table, because it's uncertain
+                          which of the key/value pair is freed and which not, while the code
+                          below expects to have freed both. */
+                       uri_query = soup_form_decode (soup_uri->query);
+
+                       g_hash_table_iter_init (&iter, uri_query);
+                       while (g_hash_table_iter_next (&iter, &key, &value)) {
+                               g_hash_table_insert (query, g_strdup (key), g_strdup (value));
+                       }
+
+                       g_hash_table_unref (uri_query);
+               }
+
+               g_hash_table_insert (query, g_strdup ("__evo-mail"), soup_uri_encode (mail_uri, NULL));
 
                /* Required, because soup_uri_set_query_from_form() can change
                   order of arguments, then the URL checksum doesn't match. */
@@ -1766,14 +1781,13 @@ mail_display_uri_requested_cb (EWebView *web_view,
                        e_mail_display_claim_skipped_uri (display, uri);
                }
 
-               g_free (mail_uri);
-
                soup_uri_set_query_from_form (soup_uri, query);
 
                new_uri = soup_uri_to_string (soup_uri, FALSE);
 
                soup_uri_free (soup_uri);
                g_hash_table_unref (query);
+               g_free (mail_uri);
 
                g_free (*redirect_to_uri);
                *redirect_to_uri = new_uri;