Merge branch 'fc/completion-updates' into maint

Command line completion updates.

* fc/completion-updates:
  completion: bash: add correct suffix in variables
  completion: bash: fix for multiple dash commands
  completion: bash: fix for suboptions with value
  completion: bash: fix prefix detection in branch.*

diff --cc contrib/completion/git-completion.bash
Simple merge

diff --cc t/t9902-completion.sh
Simple merge