tree 01ed71d20d5441b1ea57e31cc248196acd90c4a8
parent c76e1ad98a635a7c069d7ab43d31fcf38381facc
author Ian Cottrell <iancottrell@google.com> 1541445856 -0500
committer Ian Cottrell <iancottrell@google.com> 1541452882 +0000

go/packages: fix crash

This is based on 147340 and has the same test, but with a different fix.
We now produce a nice error if there is an empty root, instead of
crashing, and the cause of empty roots in go list has been fixed.
The underlying call to go list is returning the same package more than
once, and we only fix the first entry in the root list, so the second
one got left blank.
The fix was to not add the second duplicate copy to the output of the
driver at all.

Change-Id: I9f1b2f0fd63635ba101cdd3c8a5108530e968ba9
Reviewed-on: https://go-review.googlesource.com/c/147440
Run-TryBot: Ian Cottrell <iancottrell@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michael Matloob <matloob@golang.org>