From 200eeffeee2fb535b326fb2a7e17d87b49ab83ea Mon Sep 17 00:00:00 2001
From: Johannes Altmanninger <aclopte@gmail.com>
Date: Sun, 2 Mar 2025 11:21:14 +0100
Subject: [PATCH] sample_prompts/acidhub: fix regression showing all branches

Fix the accidental "git branch" output leaking while making sure we support:
1. unborn branch, where HEAD does not exist (`git init`)
2. detached head (`git checkout --detach`)

Notably computing the branch name should be independent of computing
a diff against HEAD.
In scenario 1 there is a branch but no HEAD,
while in scenario 2 it's the other way round.

Hence we need a separate check to see if we're in a git repo.
"git rev-parse" seems to work. Not sure what's best pracitce.

Also remove the ahead/behind logic, it was broken because it misspelled
@{upstream}.

Fixes #11179

(cherry picked from commit 7b7e7443538a741474c33c8d8c2d6b0f4c950001)
---
 .../web_config/sample_prompts/acidhub.fish    | 24 +++++++------------
 1 file changed, 9 insertions(+), 15 deletions(-)

diff --git a/share/tools/web_config/sample_prompts/acidhub.fish b/share/tools/web_config/sample_prompts/acidhub.fish
index 61a5078d2..1a692209e 100644
--- a/share/tools/web_config/sample_prompts/acidhub.fish
+++ b/share/tools/web_config/sample_prompts/acidhub.fish
@@ -5,18 +5,15 @@ function fish_prompt -d "Write out the prompt"
     set -l laststatus $status
 
     set -l git_info
-    if set -l git_branch (command git branch --format=%\(refname:lstrip=2\) 2> /dev/null)
+    if git rev-parse 2>/dev/null
+        set -l git_branch (
+            { command git symbolic-ref HEAD 2>/dev/null || echo - } |
+            string replace refs/heads/ '')
+        set git_branch (set_color -o blue)"$git_branch"
         set -l git_status
-        if test -n "$git_branch"; and not command git diff-index --quiet HEAD --
-            if set -l count (command git rev-list --count --left-right $upstream...HEAD 2>/dev/null)
-                echo $count | read -l ahead behind
-                if test "$ahead" -gt 0
-                    set git_status "$git_status"(set_color red)⬆
-                end
-                if test "$behind" -gt 0
-                    set git_status "$git_status"(set_color red)⬇
-                end
-            end
+        if git rev-parse --quiet --verify HEAD >/dev/null
+            and not command git diff-index --quiet HEAD --
+
             for i in (git status --porcelain | string sub -l 2 | sort | uniq)
                 switch $i
                     case "."
@@ -35,11 +32,8 @@ function fish_prompt -d "Write out the prompt"
             end
         else
             set git_status (set_color green):
-            if test -z "$git_branch"
-                set git_branch -
-            end
         end
-        set git_info "(git$git_status"(set_color -o blue)"$git_branch"(set_color white)")"
+        set git_info "(git$git_status$git_branch"(set_color white)")"
     end
 
     # Disable PWD shortening by default.