ldlinux: Only append missing filename extensions

Don't append an extension like ".c32" if the command already has one!
This bug lead to "config.c32" being executed as "config.c32.c32" with
the below config snippet,

    LABEL config
        COM32 config.c32 /configs/isolinux.cfg

Reported-by: Ady <ady-sf@hotmail.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

diff --git a/com32/elflink/ldlinux/ldlinux.c b/com32/elflink/ldlinux/ldlinux.c
index 82d2ae6..62db2f7 100644 (file)
--- a/com32/elflink/ldlinux/ldlinux.c
+++ b/com32/elflink/ldlinux/ldlinux.c
@@ -121,12 +121,15 @@ const char *apply_extension(const char *kernel, const char *ext)
        memcpy(k, kernel, len);
 
        /* Append the extension */
-       memcpy(k + len, ext, elen);
+       if (strncmp(p - elen, ext, elen)) {
+               memcpy(k + len, ext, elen);
+               len += elen;
+       }
 
        /* Copy the rest of the command line */
-       strcpy(k + len + elen, p);
+       strcpy(k + len, p);
 
-       k[len + elen + strlen(p)] = '\0';
+       k[len + strlen(p)] = '\0';
 
        return k;
 }