Fix newly introduced compiler warning

(cherry picked from commit ab8177de2c89672e63a7a1ccef4df8f7bf34fbd2)

diff --git a/ext/soap/php_sdl.c b/ext/soap/php_sdl.c
index 67ab4097c2d7a7a58c5aea9ef0c9edbca8349695..ee7d6045207bdc3bccd167f897fdabce1bc17191 100644 (file)
--- a/ext/soap/php_sdl.c
+++ b/ext/soap/php_sdl.c
@@ -313,7 +313,7 @@ void sdl_restore_uri_credentials(sdlCtx *ctx)
        ctx->context = NULL;
 }
 
-#define SAFE_STR(a) ((a)?a:"")
+#define SAFE_STR(a) ((a)?((const char *)a):"")
 
 static void load_wsdl_ex(zval *this_ptr, char *struri, sdlCtx *ctx, int include)
 {