From a2b1a408a804cf865cf0078b8723782b27977763 Mon Sep 17 00:00:00 2001
From: Oldes <oldes.huhuman@gmail.com>
Date: Mon, 22 Feb 2021 11:49:45 +0100
Subject: [PATCH] FIX: updating `PWD` system environment variable after each
 directory change

resolves: https://github.com/Oldes/Rebol-issues/issues/2448
---
 src/os/posix/host-lib.c      |  8 +++++++-
 src/os/win32/host-lib.c      |  8 +++++++-
 src/tests/units/port-test.r3 | 25 +++++++++++++++----------
 3 files changed, 29 insertions(+), 12 deletions(-)

diff --git a/src/os/posix/host-lib.c b/src/os/posix/host-lib.c
index d04e880b25..3db8fb2964 100644
--- a/src/os/posix/host-lib.c
+++ b/src/os/posix/host-lib.c
@@ -653,7 +653,13 @@ int pipe2(int pipefd[2], int flags); //to avoid "implicit-function-declaration"
 **
 ***********************************************************************/
 {
-	return (chdir(path) == 0) ? 0 : errno;
+	if (chdir(path) == 0) {
+		// directory changed... update PWD
+		// https://github.com/Oldes/Rebol-issues/issues/2448
+		setenv("PWD", path, 1);
+		return 0;
+	} else
+		return errno;
 }
 
 
diff --git a/src/os/win32/host-lib.c b/src/os/win32/host-lib.c
index 8d93c04eea..0e93013054 100644
--- a/src/os/win32/host-lib.c
+++ b/src/os/win32/host-lib.c
@@ -649,7 +649,13 @@ static void *Task_Ready;
 **
 ***********************************************************************/
 {
-	return (SetCurrentDirectory(path[0] == 0 ? L"\\" : path)) ? 0 : GetLastError();
+	if (SetCurrentDirectory(path[0] == 0 ? L"\\" : path)) {
+		// directory changed... update PWD
+		// https://github.com/Oldes/Rebol-issues/issues/2448
+		SetEnvironmentVariable(L"PWD", path);
+		return 0;
+	} else
+		return GetLastError();
 }
 
 
diff --git a/src/tests/units/port-test.r3 b/src/tests/units/port-test.r3
index 51e931d5c1..487ce925bc 100644
--- a/src/tests/units/port-test.r3
+++ b/src/tests/units/port-test.r3
@@ -138,16 +138,6 @@ Rebol [
 		;@@ https://github.com/Oldes/Rebol-issues/issues/2447
 		--assert false? try [delete %not-exists/]
 		--assert error? try [delete %/]
-
-	--test-- "CHANGE-DIR"
-		;@@ https://github.com/Oldes/Rebol-issues/issues/2446
-		--assert what-dir = change-dir %.
-		--assert all [
-			error? e: try [change-dir %issues/2446]
-			e/id = 'cannot-open
-			e/arg1 = join what-dir %issues/2446/
-		]
-		
 if system/platform = 'Windows [
 ;@@ it looks that on Linux there is no lock on opened file
 		--assert all [
@@ -169,6 +159,21 @@ if system/platform = 'Windows [
 		]
 ]
 
+	--test-- "CHANGE-DIR"
+		;@@ https://github.com/Oldes/Rebol-issues/issues/2446
+		--assert what-dir = change-dir %.
+		--assert all [
+			error? e: try [change-dir %issues/2446]
+			e/id = 'cannot-open
+			e/arg1 = join what-dir %issues/2446/
+		]
+		;@@ https://github.com/Oldes/Rebol-issues/issues/2448
+		dir: pwd
+		--assert pwd = to-rebol-file get-env "PWD"
+		change-dir %../
+		--assert pwd = to-rebol-file get-env "PWD"
+		change-dir dir
+
 	--test-- "RENAME dir"
 		;@@ https://github.com/Oldes/Rebol-issues/issues/1533
 		--assert all [