Added new function git_remote_status to check if we are ahead, behind or diverged from the remote branch

lib/git.zsh

@@ -4,6 +4,7 @@ function git_prompt_info() {
   echo "$ZSH_THEME_GIT_PROMPT_PREFIX${ref#refs/heads/}$(parse_git_dirty)$ZSH_THEME_GIT_PROMPT_SUFFIX"
 }
 
+# get dirty status of the current working tree
 parse_git_dirty () {
   if [[ -n $(git status -s 2> /dev/null) ]]; then
     echo "$ZSH_THEME_GIT_PROMPT_DIRTY"
@@ -12,6 +13,26 @@ parse_git_dirty () {
   fi
 }
 
+# get the difference between the local and remote branches
+git_remote_status() {
+    remote=${$(git rev-parse --verify ${hook_com[branch]}@{upstream} --symbolic-full-name 2>/dev/null)/refs\/remotes\/}
+    if [[ -n ${remote} ]] ; then
+        ahead=$(git rev-list ${hook_com[branch]}@{upstream}..HEAD 2>/dev/null | wc -l)
+        behind=$(git rev-list HEAD..${hook_com[branch]}@{upstream} 2>/dev/null | wc -l)
+
+        if [ $ahead -eq 0 ] && [ $behind -gt 0 ]
+        then
+            echo "$ZSH_THEME_GIT_PROMPT_BEHIND_REMOTE"
+        elif [ $ahead -gt 0 ] && [ $behind -eq 0 ]
+        then
+            echo "$ZSH_THEME_GIT_PROMPT_AHEAD_REMOTE"
+        elif [ $ahead -gt 0 ] && [ $behind -gt 0 ]
+        then
+            echo "$ZSH_THEME_GIT_PROMPT_DIVERGED_REMOTE"
+        fi
+    fi
+}
+
 # get the status of the working tree
 git_prompt_status() {
   INDEX=$(git status --porcelain 2> /dev/null)