1. Assigning: "decoded" = storage returned from "g_strndup(part, length)"
2. leaked_storage: Variable "decoded" going out of scope leaks the storage it points to.

uri_decoded_copy (const char *part, int length, int *decoded_length)
{
	unsigned char *s, *d;
	char *decoded = g_strndup (part, length);

	g_return_val_if_fail (part != NULL, NULL); <== memory issue

	s = d = (unsigned char *)decoded;

        ....

        return decoded;
}

------------------------ patch option 1 --------------------------
--- a/libsoup/soup-uri.c
+++ b/libsoup/soup-uri.c
@@ -724,7 +724,7 @@ uri_decoded_copy (const char *part, int length, int *decoded_length)
     unsigned char *s, *d;
     char *decoded = g_strndup (part, length);

-    g_return_val_if_fail (part != NULL, NULL);
+    g_return_val_if_fail (decoded != NULL, NULL);

     s = d = (unsigned char *)decoded;
     do {

------------------------ patch option 2 --------------------------
--- a/libsoup/soup-uri.c
+++ b/libsoup/soup-uri.c
@@ -722,10 +722,13 @@ char *
 uri_decoded_copy (const char *part, int length, int *decoded_length)
 {
     unsigned char *s, *d;
-    char *decoded = g_strndup (part, length);

     g_return_val_if_fail (part != NULL, NULL);

+    char *decoded = g_strndup (part, length);
+
+    g_return_val_if_fail (decoded != NULL, NULL);
+
     s = d = (unsigned char *)decoded;
     do {
        if (*s == '%') {