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>
3 files changed
tree: 01ed71d20d5441b1ea57e31cc248196acd90c4a8
  1. benchmark/
  2. blog/
  3. cmd/
  4. container/
  5. cover/
  6. go/
  7. godoc/
  8. imports/
  9. internal/
  10. playground/
  11. present/
  12. refactor/
  13. third_party/
  14. .gitattributes
  15. .gitignore
  16. AUTHORS
  17. codereview.cfg
  18. CONTRIBUTING.md
  19. CONTRIBUTORS
  20. LICENSE
  21. PATENTS
  22. README.md
README.md

Go Tools

This subrepository holds the source for various packages and tools that support the Go programming language.

Some of the tools, godoc and vet for example, are included in binary Go distributions.

Others, including the Go guru and the test coverage tool, can be fetched with go get.

Packages include a type-checker for Go and an implementation of the Static Single Assignment form (SSA) representation for Go programs.

Download/Install

The easiest way to install is to run go get -u golang.org/x/tools/.... You can also manually git clone the repository to $GOPATH/src/golang.org/x/tools.

Report Issues / Send Patches

This repository uses Gerrit for code changes. To learn how to submit changes to this repository, see https://golang.org/doc/contribute.html.

The main issue tracker for the tools repository is located at https://github.com/golang/go/issues. Prefix your issue with “x/tools/(your subdir):” in the subject line, so it is easy to find.