Merge branch 'jk/complete-merge-pull' into maint

The completion scripts (in contrib/) did not know about quite a few
options that are common between "git merge" and "git pull", and a
couple of options unique to "git merge".

* jk/complete-merge-pull:
  completion: add missing options for git-merge
  completion: add a note that merge options are shared

contrib/completion/git-completion.bash

@@ -1472,9 +1472,12 @@ _git_log ()
 	__git_complete_revlist
 }
 
+# Common merge options shared by git-merge(1) and git-pull(1).
 __git_merge_options="
 	--no-commit --no-stat --log --no-log --squash --strategy
 	--commit --stat --no-squash --ff --no-ff --ff-only --edit --no-edit
+	--verify-signatures --no-verify-signatures --gpg-sign
+	--quiet --verbose --progress --no-progress
 "
 
 _git_merge ()
@@ -1483,7 +1486,8 @@ _git_merge ()
 
 	case "$cur" in
 	--*)
-		__gitcomp "$__git_merge_options"
+		__gitcomp "$__git_merge_options
+			--rerere-autoupdate --no-rerere-autoupdate --abort"
 		return
 	esac
 	__gitcomp_nl "$(__git_refs)"