From faa95a784d2c74c72e70367a5d531df6dd61aeab Mon Sep 17 00:00:00 2001
From: Steve Purcell <steve@sanityinc.com>
Date: Sun, 6 Aug 2023 16:41:48 +0200
Subject: [PATCH] Don't redefine built-in function

Fixes #1817
---
 tests/haskell-indent-tests.el      | 14 ++++++++------
 tests/haskell-indentation-tests.el | 14 ++++++++------
 2 files changed, 16 insertions(+), 12 deletions(-)

diff --git a/tests/haskell-indent-tests.el b/tests/haskell-indent-tests.el
index 7196405b8..9a3de4ad3 100644
--- a/tests/haskell-indent-tests.el
+++ b/tests/haskell-indent-tests.el
@@ -40,11 +40,13 @@
 ;;                    (haskell-indent-put-region-in-literate (point-min) (point-max) -1)
 ;;                    (buffer-substring-no-properties (point-min) (point-max))))))
 
-(defsubst string-trim-left (string)
-  "Remove leading whitespace from STRING."
-  (if (string-match "\\`[ \t\n\r]+" string)
-      (replace-match "" t t string)
-    string))
+(if (fboundp 'string-trim-left)
+    (defalias 'haskell--string-trim-left 'string-trim-left)
+  (defun haskell--string-trim-left (string &optional regexp)
+    "Remove leading whitespace from STRING."
+    (if (string-match (concat "\\`\\(?:" (or regexp "[ \t\n\r]+") "\\)") string)
+        (substring string (match-end 0))
+      string)))
 
 (defun haskell-indent-format-info (info)
   (if (cdr info)
@@ -128,7 +130,7 @@ macro quotes them for you."
          :expected-result
          ,(if allow-failure :failed :passed)
          (haskell-indent-check
-          ,(string-trim-left source)
+          ,(haskell--string-trim-left source)
           ,@(mapcar (lambda (x)
                       (list 'quote x))
                     test-cases))))))
diff --git a/tests/haskell-indentation-tests.el b/tests/haskell-indentation-tests.el
index 4889b76a7..cd783a4f4 100644
--- a/tests/haskell-indentation-tests.el
+++ b/tests/haskell-indentation-tests.el
@@ -33,11 +33,13 @@
 
 ;;; Code:
 
-(defsubst string-trim-left (string)
-  "Remove leading whitespace from STRING."
-  (if (string-match "\\`[ \t\n\r]+" string)
-      (replace-match "" t t string)
-    string))
+(if (fboundp 'string-trim-left)
+    (defalias 'haskell--string-trim-left 'string-trim-left)
+  (defun haskell--string-trim-left (string &optional regexp)
+    "Remove leading whitespace from STRING."
+    (if (string-match (concat "\\`\\(?:" (or regexp "[ \t\n\r]+") "\\)") string)
+        (substring string (match-end 0))
+      string)))
 
 (defun haskell-indentation-check (source &rest test-cases)
   "Check if `haskell-indentation-find-indentations' returns expected results.
@@ -115,7 +117,7 @@ macro quotes them for you."
          :expected-result
          ,(if allow-failure :failed :passed)
          (haskell-indentation-check
-          ,(string-trim-left source)
+          ,(haskell--string-trim-left source)
           ,@(mapcar (lambda (x)
                       (list 'quote x))
                     test-cases))))))