git-compose can now be cancelled with :q! in neovim

overlay/scripts/commands/git-compose.nix

@@ -6,6 +6,8 @@ pkgs.writeShellApplication {
     gawk
   ];
   text = ''
+    set -e
+
     toplevel=$(git rev-parse --show-toplevel 2>/dev/null)
 
     if [ -z "$toplevel" ]; then
@@ -16,7 +18,6 @@ pkgs.writeShellApplication {
     (
       cd "$toplevel" || { echo "Failed to change to repo root"; exit 1; }
 
-      git reset > /dev/null 2>&1
       unstaged=$(git status --porcelain | awk '{print $2}') || { echo "Failed to get git status"; exit 1; }
 
       if [ -z "$unstaged" ]; then
@@ -24,11 +25,14 @@ pkgs.writeShellApplication {
         exit 0
       fi
 
+      git reset > /dev/null 2>&1
+
       tmpfile=$(mktemp) || { echo "Failed to create a temporary file"; exit 1; }
       trap 'rm -f "$tmpfile"' EXIT
 
-      {
+      filecontent=$(
         echo "# Compose your commits here"
+        echo "# To cancel this operation, exit without saving (e.g., :q!)"
         echo "#"
         echo "# Format should be as follows:"
         echo "# <some_commit_message>"
@@ -41,10 +45,16 @@ pkgs.writeShellApplication {
         echo "# using the given commit message at the top of the group"
         echo
         echo "$unstaged"
-      } >> "$tmpfile"
+      )
+      echo "$filecontent" > "$tmpfile"
 
       nvim -c 'setfiletype gitcommit' "$tmpfile"
 
+      if [ "$(cat "$tmpfile")" = "$filecontent" ]; then
+        echo "No changes found; cancelling composition."
+        exit 1
+      fi
+
       collecting=false
       msg=""
       lines=()
@@ -63,7 +73,7 @@ pkgs.writeShellApplication {
           collecting=true
           msg="$line"
         else
-          lines+=("$line")
+          lines+=("./$line")
         fi
       done < "$tmpfile"