Don't require image num/name when applying from single-image pipable WIM

[wimlib] / src / extract.c

diff --git a/src/extract.c b/src/extract.c
index 95071bd7bfbb35b45dec106755a88b1c0db204e8..092c8c4033a26659ee270ddf406d5d63d328bd1a 100644 (file)
--- a/src/extract.c
+++ b/src/extract.c
@@ -2629,16 +2629,26 @@ wimlib_extract_image_from_pipe(int pipe_fd, const tchar *image_num_or_name,
 
        /* Get image index (this may use the XML data that was just read to
         * resolve an image name).  */
-       image = wimlib_resolve_image(pwm, image_num_or_name);
-       if (image == WIMLIB_NO_IMAGE) {
-               ERROR("\"%"TS"\" is not a valid image in the pipable WIM!",
-                     image_num_or_name);
-               ret = WIMLIB_ERR_INVALID_IMAGE;
-               goto out_wimlib_free;
-       } else if (image == WIMLIB_ALL_IMAGES) {
-               ERROR("Applying all images from a pipe is not supported.");
-               ret = WIMLIB_ERR_INVALID_IMAGE;
-               goto out_wimlib_free;
+       if (image_num_or_name) {
+               image = wimlib_resolve_image(pwm, image_num_or_name);
+               if (image == WIMLIB_NO_IMAGE) {
+                       ERROR("\"%"TS"\" is not a valid image in the pipable WIM!",
+                             image_num_or_name);
+                       ret = WIMLIB_ERR_INVALID_IMAGE;
+                       goto out_wimlib_free;
+               } else if (image == WIMLIB_ALL_IMAGES) {
+                       ERROR("Applying all images from a pipe is not supported.");
+                       ret = WIMLIB_ERR_INVALID_IMAGE;
+                       goto out_wimlib_free;
+               }
+       } else {
+               if (pwm->hdr.image_count != 1) {
+                       ERROR("No image was specified, but the pipable WIM "
+                             "did not contain exactly 1 image");
+                       ret = WIMLIB_ERR_INVALID_IMAGE;
+                       goto out_wimlib_free;
+               }
+               image = 1;
        }
 
        /* Load the needed metadata resource.  */