feature: check if file is already on git repository...

when applying to the stage area, if the file
is not already commited on the repository
the patch will fail.

we show the option only if the file
is already commited.

lib/app/interactive/interactive.ml

@@ -160,7 +160,7 @@ let apply_patch_with_cmd cmd hunk_patch =
   >>= fun () -> process#close
 
 let apply_patch_with_git hunk_patch =
-  apply_patch_with_cmd "git apply --index" hunk_patch
+  apply_patch_with_cmd "git apply --index --intent-to-add" hunk_patch
 
 let apply_patch hunk_patch =
   apply_patch_with_cmd "patch -p 0" hunk_patch
@@ -169,7 +169,24 @@ let drop_into_editor editor path ~at_line =
   let command = Format.sprintf "%s +%d %s" editor at_line path in
   Lwt_unix.system command
 
+let file_in_git_repo path =
+  let command = Format.sprintf "test ! -z \"$(git ls-files -- %s)\"" path in
+  Lwt_unix.system command
+  >>= fun status ->
+  match status with
+  | Lwt_unix.WEXITED x -> return (x == 0)
+  | _ -> return false
+
 let process_input default_is_accept hunk_patch prev_start next_start editor path ~continue =
+  file_in_git_repo path
+  >>= fun file_gited ->
+  let git_option =
+    if file_gited then
+      [ "\x1b[32m"
+      ; "g = accept as git patch"
+      ; "\x1b[0m"
+      ; ", "
+      ] else [] in
   let prompt =
     if default_is_accept then
       [ "Accept change ("
@@ -179,11 +196,8 @@ let process_input default_is_accept hunk_patch prev_start next_start editor path
       ; "\x1b[1m"
       ; " [default], "
       ; "\x1b[0m"
-      ; "\x1b[32m"
-      ; "g = accept as git patch"
-      ; "\x1b[0m"
-      ; ", "
-      ; "\x1b[31m"
+      ] @ git_option @ [
+        "\x1b[31m"
       ; "n = no"
       ; "\x1b[0m"
       ; ", "
@@ -203,11 +217,8 @@ let process_input default_is_accept hunk_patch prev_start next_start editor path
       ; "y = yes"
       ; "\x1b[0m"
       ; ", "
-      ; "\x1b[32m"
-      ; "g = accept as git patch"
-      ; "\x1b[0m"
-      ; ", "
-      ; "\x1b[31m"
+      ] @ git_option @ [
+        "\x1b[31m"
       ; "n = no"
       ; "\x1b[0m"
       ; "\x1b[1m"
@@ -234,7 +245,8 @@ let process_input default_is_accept hunk_patch prev_start next_start editor path
     | "y" -> apply_patch hunk_patch >>= handle_patch_errors >>= fun _ -> continue ()
     | "" when default_is_accept ->
       apply_patch hunk_patch >>= handle_patch_errors >>= fun _ -> continue ()
-    | "g" -> apply_patch_with_git hunk_patch >>= handle_patch_errors >>= fun _ -> continue ()
+    | "g" when file_gited -> apply_patch_with_git hunk_patch >>= handle_patch_errors >>= fun _ -> continue ()
+    | "g" when not file_gited -> Lwt_io.printl "File is not on repository. Try again." >>= try_again
     | "n" -> continue ()
     | "" when not default_is_accept -> continue ()
     | "e" ->