Update theme git prompt

We finally reduce the number of calls to `git status` by overriding
`parse_git_dirty`. More variables are also given local scope, although not sure
if this improves anything. At the rate we are overriding omz library functions,
we should perhaps make the theme entirely self-sufficient, and then see if we
can move to prezto...

zsh/custom/cinaeco.zsh-theme

@@ -26,6 +26,7 @@ ZSH_THEME_GIT_INDEX_COPIED="c"
 ZSH_THEME_GIT_PROMPT_BEHIND_REMOTE=" BEHIND"
 ZSH_THEME_GIT_PROMPT_AHEAD_REMOTE=" AHEAD"
 ZSH_THEME_GIT_PROMPT_DIVERGED_REMOTE=" %{$fg[red]%}DIVERGED!"
+DISABLE_UNTRACKED_FILES_DIRTY="false"
 
 ##############################
 # FUNCTIONS
@@ -43,6 +44,18 @@ function background_job_info() {
   echo "  %(1j.%{$FG[063]%}[jobs]: %{$fg[red]%}%j%{$reset_color%}.)"
 }
 
+# Set Up List of Git Status Indicators
+#
+# This function retrieves a porcelain `git status` for use in other functions,
+# `git_prompt_status` and `parse_git_dirty`.
+get_git_status() {
+  local FLAGS
+  FLAGS=("--porcelain")
+  [[ $POST_1_7_2_GIT -gt 0 ]] && FLAGS+="--ignore-submodules=dirty"
+  [[ $DISABLE_UNTRACKED_FILES_DIRTY == "true" ]] && FLAGS+="--untracked-files=no"
+  INDEX=$(git status $FLAGS 2> /dev/null)
+}
+
 # Display Git repo information in prompt (override the default omz function)
 #
 # Displays [repo:branch:commit] BISECT/MERGE/REBASE AHEAD/BEHIND/DIVERGED! +±xcrU?
@@ -50,12 +63,12 @@ function background_job_info() {
 # Git commit id and mode code taken from:
 # https://github.com/benhoskings/dot-files/blob/master/files/bin/git_cwd_info
 function git_prompt_info() {
-  GIT_REPO_PATH=$(git rev-parse --git-dir 2>/dev/null)
+  local GIT_REPO_PATH=$(git rev-parse --git-dir 2>/dev/null)
   [[ $GIT_REPO_PATH == "" ]] && return
 
-  GIT_COMMIT_ID=`git rev-parse --short HEAD 2>/dev/null`
+  local GIT_COMMIT_ID=`git rev-parse --short HEAD 2>/dev/null`
 
-  GIT_MODE="%{$fg[magenta]%}"
+  local GIT_MODE="%{$fg[magenta]%}"
   if [[ -e "$GIT_REPO_PATH/BISECT_LOG" ]]; then
     GIT_MODE="$GIT_MODE BISECT"
   elif [[ -e "$GIT_REPO_PATH/MERGE_HEAD" ]]; then
@@ -64,15 +77,14 @@ function git_prompt_info() {
     GIT_MODE="$GIT_MODE REBASE"
   fi
 
-  GIT_STASH=""
+  local GIT_STASH=""
   if [[ -e "$GIT_REPO_PATH/refs/stash" ]]; then
     GIT_STASH=" %{$fg[red]%}STASH"
   fi
 
-  GIT_BRANCH=$(current_branch)
-  [[ $GIT_BRANCH == '' ]] && GIT_BRANCH="%{$fg[red]%}no branch$(parse_git_dirty)"
+  get_git_status
 
-  echo "  $(parse_git_dirty)$ZSH_THEME_GIT_PROMPT_PREFIX$(current_repository):$GIT_BRANCH:$GIT_COMMIT_ID$ZSH_THEME_GIT_PROMPT_SUFFIX$GIT_MODE$(git_remote_status)$GIT_STASH$(git_prompt_status)"
+  echo "  $(parse_git_dirty)$ZSH_THEME_GIT_PROMPT_PREFIX$(current_repository):$(current_branch):$GIT_COMMIT_ID$ZSH_THEME_GIT_PROMPT_SUFFIX$GIT_MODE$(git_remote_status)$GIT_STASH$(git_prompt_status)"
 }
 
 # Git Change Indication (overriding default omz function)
@@ -80,17 +92,15 @@ function git_prompt_info() {
 # Prints symbol for each change instead of just indicating if change type exists.
 # This gives a better visual sense of how much has changed.
 #
-# TODO If you find prompt speed slow, it's because of this section.
-# The limitation is the speed of `git status` in any given repo (it's slower
-# than you'd imagine).
-# This can be countered somewhat by ignoring submodules. We lose reporting of
-# submodule changes in prompt, but the speed is much better.
-# The rest of the status string building is near-instantaneous.
+# As big as it looks, this function's status-string building is
+# near-instantaneous. It's just string manipulation after all.
+#
+# If you find prompt speed slow, it's because of the speed of `git status` in
+# any given repo: it's slower than you'd imagine.
 git_prompt_status() {
-  local SUBMODULE_SYNTAX=''
-  [[ $POST_1_7_2_GIT -gt 0 ]] && SUBMODULE_SYNTAX="--ignore-submodules=dirty"
-  INDEX=$(git status --porcelain $SUBMODULE_SYNTAX 2> /dev/null)
   [[ -z $INDEX ]] && return
+  local X
+  local Y
   local X_SET=""
   local Y_SET=""
   local UN_SET=""
@@ -119,9 +129,21 @@ git_prompt_status() {
 # Read the current repository (override the default omz function)
 #
 # Cope with non-ssh repos by not relying on ':'. Instead, we look for text
-# between a '/' and '.git'.
-# TODO should expand to search between '/' and space, if '.git' is not present.
-# Some people don't write their remotes properly.
+# between a '/' and whitespace. '.git' is removed.
 function current_repository() {
-  echo $(git remote -v | head -1 | sed 's/.*\/\([^/]*\)\.git.*/\1/')
+  local repo=$(git remote -v | head -1 | sed 's/.*\/\([^/]*\)\ .*/\1/')
+  echo ${repo%.git}
+}
+
+# Check if a repo is modified (override the default omz function)
+#
+# This function is modifed to no longer run `git status`, and to instead rely on
+# the output of the single invocation in `get_git_status`. This way, we
+# hopefully reduce the time taken to produce a prompt in messy repos.
+parse_git_dirty() {
+  if [[ -n $INDEX ]]; then
+    echo "$ZSH_THEME_GIT_PROMPT_DIRTY"
+  else
+    echo "$ZSH_THEME_GIT_PROMPT_CLEAN"
+  fi
 }