Cannot copy blob from implicit root container

[jcookems]

Most of the blob APIs allow the the user to pass the empty string as the container name to indicate the implicit root container (as opposed to being explicit, using "$root").

However, that does not work for the source container's name when using the copyBlob API. Looking at the headers sent out, the problems is that the source is malformed with a double slash in the middle:

X-Ms-Copy-Source: /XXX//qa-214273-int-39

The problem in in BlobRestProxy.getCopyBlobSourceName, where source container is checked for null, but not empty. The fix is to change:

-    if (sourceContainer != null) {
+    if (sourceContainer != null && !sourceContainer.isEmpty()) {

[gcheng]

We should have unit test for scenario like this.

[gcheng]

no longer in scope