Exceptions thrown in CommandOutputHandler.process() may not be propagated if it’s thrown after git process exits.

Issue Summary

Exceptions thrown in CommandOutputHandler.process() may not be propagated if it’s thrown after the git process exits. This issue is related to https://jira.atlassian.com/browse/BSERV-13350

This is reproducible on Data Center: (yes)

Steps to Reproduce

1. In CommandOutputHandler.process, consume all the git output, so that git exists successfully. (i.e. drain the InputStream until it is empty)
2. Sleep 5 seconds
3. Throw an exception.

Expected Results

Exceptions thrown in CommandOutputHandler.process() method are propagated even after the git process exited.

Actual Results

Exceptions are not propagated after the git process exits.

Workaround

No workaround.