completion: fix bugs with slashes in remote names

Previously, some calls to for-each-ref passed fixed numbers of path
components to strip from refs, assuming that remote names had no slashes
in them. This made completions like:

git push github/dseomn :com<Tab>

Result in:

git push github/dseomn :dseomn/completion-remote-slash

With this patch, it instead results in:

git push github/dseomn :completion-remote-slash

Signed-off-by: David Mandelberg <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: dseomn

contrib/completion/git-completion.bash

@@ -790,16 +790,39 @@ __git_tags ()
 __git_dwim_remote_heads ()
 {
 	local pfx="${1-}" cur_="${2-}" sfx="${3-}"
-	local fer_pfx="${pfx//\%/%%}" # "escape" for-each-ref format specifiers
 
 	# employ the heuristic used by git checkout and git switch
 	# Try to find a remote branch that cur_es the completion word
 	# but only output if the branch name is unique
-	__git for-each-ref --format="$fer_pfx%(refname:strip=3)$sfx" \
-		--sort="refname:strip=3" \
-		${GIT_COMPLETION_IGNORE_CASE+--ignore-case} \
-		"refs/remotes/*/$cur_*" "refs/remotes/*/$cur_*/**" | \
-	uniq -u
+	local awk_script='
+	function casemap(s) {
+		if (ENVIRON["IGNORE_CASE"])
+			return tolower(s)
+		else
+			return s
+	}
+	BEGIN {
+		split(ENVIRON["REMOTES"], remotes, /\n/)
+		for (i in remotes)
+			remotes[i] = "refs/remotes/" casemap(remotes[i])
+		cur_ = casemap(ENVIRON["CUR_"])
+	}
+	{
+		ref_case = casemap($0)
+		for (i in remotes) {
+			if (index(ref_case, remotes[i] "/" cur_) == 1) {
+				branch = substr($0, length(remotes[i] "/") + 1)
+				print ENVIRON["PFX"] branch ENVIRON["SFX"]
+				break
+			}
+		}
+	}
+	'
+	__git for-each-ref --format='%(refname)' refs/remotes/ |
+		PFX="$pfx" SFX="$sfx" CUR_="$cur_" \
+			IGNORE_CASE=${GIT_COMPLETION_IGNORE_CASE+1} \
+			REMOTES="$(__git_remotes | sort -r)" awk "$awk_script" |
+		sort | uniq -u
 }
 
 # Lists refs from the local (by default) or from a remote repository.
@@ -905,7 +928,8 @@ __git_refs ()
 			case "HEAD" in
 			$match*|$umatch*)	echo "${pfx}HEAD$sfx" ;;
 			esac
-			__git for-each-ref --format="$fer_pfx%(refname:strip=3)$sfx" \
+			local strip="$(__git_count_path_components "refs/remotes/$remote")"
+			__git for-each-ref --format="$fer_pfx%(refname:strip=$strip)$sfx" \
 				${GIT_COMPLETION_IGNORE_CASE+--ignore-case} \
 				"refs/remotes/$remote/$match*" \
 				"refs/remotes/$remote/$match*/**"