go/analysis/internal/checker: don't clobber error when packages.Load fails

Previously, if `packages.Load` failed, it would (sometimes? always?) return an error + no initial packages.
The moved `len(initial)` check was overriding the actual err with a much less useful one.

Example output before:
```
13:03:17.856866 load [./...]
13:03:28.403532 ./... matched no packages
```
And after:
```
13:03:30.942191 load [./...]
13:03:36.999506 go list repeated package [an internal package] with different values
```

Change-Id: I1a821e3855cbbbee904bcec9c29877e091c3e3a0
GitHub-Last-Rev: d1235fc2eceb0d4e947f47be99edc5ac96da5f84
GitHub-Pull-Request: golang/tools#65
Reviewed-on: https://go-review.googlesource.com/c/155745
Reviewed-by: Michael Matloob <matloob@golang.org>
1 file changed
tree: bd3aa17ec6581ef5992f52f7b050d01287684629
  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.