Add support for browsing GitHub tags

modules/git/functions/git-hub

@@ -5,31 +5,43 @@
 #   Sorin Ionescu <sorin.ionescu@gmail.com>
 #
 
-local remote branches branch current_branch file url
+local remotes remote references reference file url
 
 remote="${1:-origin}"
+remotes=($(
+  git config --local --get-regexp 'remote.*.url' \
+    | awk 'BEGIN {FS="."} ; {print $2}'
+))
+
+if (( $remotes[(i)$remote] == $#remotes + 1 )); then
+  print "$0: remote not found: $remote" >&2
+  return 1
+fi
+
 url=$(
   git config --local --get "remote.${remote}.url" \
     | sed -En "s/(git|https?)(@|:\/\/)github.com(:|\/)(.+)\/(.+).git/https:\/\/github.com\/\4\/\5/p"
 )
-branches=($(
-  git ls-remote --heads "$remote" \
-    | awk '{gsub(/refs\/heads\//, "", $2)} ; {print $2}'
-))
-current_branch="$(git-branch-current)"
-branch="${2:-master}"
-file="$3"
 
-if [[ -z "$2" ]]; then
-  if (( $branches[(I)$current_branch] != 0 )); then
-    branch="$current_branch"
-  else
-    branch='master'
-  fi
+reference="${${2:-$(git-branch-current)}:-HEAD}"
+references=(
+  HEAD
+  ${$(git ls-remote --heads --tags "$remote" | awk '{print $2}')##refs/(heads|tags)/}
+)
+
+if (( $references[(i)$reference] == $#references + 1 )); then
+  print "$0: branch or tag not found: $reference" >&2
+  return 1
 fi
 
+if [[ "$reference" == 'HEAD' ]]; then
+  reference="$(git rev-parse HEAD 2>/dev/null)"
+fi
+
+file="$3"
+
 if [[ -n "$url" ]]; then
-  url="${url}/tree/${branch}/${file}"
+  url="${url}/tree/${reference}/${file}"
 
   if (( $+commands[$BROWSER] )); then
     "$BROWSER" "$url"
@@ -39,7 +51,7 @@ if [[ -n "$url" ]]; then
     return 1
   fi
 else
-  print "$0: not a Git repository or remote origin not set" >&2
+  print "$0: not a Git repository or remote not set" >&2
   return 1
 fi