Add git-info diverged subcontext for prompt formatting

modules/git/README.md

@@ -254,6 +254,7 @@ setting a style is as follows.
 | action    |     %s      | Special action name
 | ahead     |     %A      | Commits ahead of remote count
 | behind    |     %B      | Commits behind of remote count
+| diverged  |     %V      | Diverged from remote state
 | branch    |     %b      | Branch name
 | commit    |     %c      | Commit hash
 | position  |     %p      | Commits from the nearest tag count

modules/git/functions/git-info

@@ -125,6 +125,8 @@ function git-info {
   local dirty=0
   local dirty_format
   local dirty_formatted
+  local diverged
+  local diverged_formatted
   local ignore_submodules
   local indexed=0
   local indexed_format
@@ -252,9 +254,14 @@ function git-info {
     # Get ahead and behind counts.
     ahead_and_behind="$(${(z)ahead_and_behind_cmd} 2> /dev/null)"
 
+    ahead="$ahead_and_behind[(w)1]"
+    behind="$ahead_and_behind[(w)2]"
+    if (( ahead > 0 )) && (( behind > 0 )); then
+      zstyle -s ':prezto:module:git:info:diverged' format 'diverged_formatted'
+    fi
+
     # Format ahead.
     if [[ -n "$ahead_format" ]]; then
-      ahead="$ahead_and_behind[(w)1]"
       if (( ahead > 0 )); then
         zformat -f ahead_formatted "$ahead_format" "A:$ahead"
       fi
@@ -262,7 +269,6 @@ function git-info {
 
     # Format behind.
     if [[ -n "$behind_format" ]]; then
-      behind="$ahead_and_behind[(w)2]"
       if (( behind > 0 )); then
         zformat -f behind_formatted "$behind_format" "B:$behind"
       fi
@@ -411,7 +417,8 @@ function git-info {
       "s:$action_formatted" \
       "S:$stashed_formatted" \
       "U:$unmerged_formatted" \
-      "u:$untracked_formatted"
+      "u:$untracked_formatted" \
+      "V:$diverged_formatted"
     git_info[$info_format]="$REPLY"
   done