Detect auto-mode for dune-project files in emacs (#4222)

This lets emacs automatically switch to dune-mode when visiting a
dune-project file.

Signed-off-by: Shon Feder <shon.feder@gmail.com>

Author: shonfeder

CHANGES.md

@@ -28,6 +28,8 @@ Unreleased
 - Improve location of variables and macros in error messages (#4205,
   @jeremiedimino)
 
+- Auto-detect `dune-project` files as `dune` files in Emacs (#4222, @shonfeder)
+
 2.8.2 (21/01/2021)
 ------------------
 

editor-integration/emacs/dune.el

@@ -395,7 +395,7 @@ For customization purposes, use `dune-mode-hook'."
 
 ;;;###autoload
 (add-to-list 'auto-mode-alist
-             '("\\(?:\\`\\|/\\)dune\\(?:\\.inc\\)?\\'" . dune-mode))
+             '("\\(?:\\`\\|/\\)dune\\(?:\\.inc\|-project\\)?\\'" . dune-mode))
 
 
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