Closes #18479: Changed venv Activate.ps1 to make deactivate a function, and removed Deactivate.ps1.

Lib/venv/scripts/nt/Activate.ps1

-$env:VIRTUAL_ENV="__VENV_DIR__"
+function global:deactivate ([switch]$NonDestructive) {
+    # Revert to original values
+    if (Test-Path function:_OLD_VIRTUAL_PROMPT) {
+        copy-item function:_OLD_VIRTUAL_PROMPT function:prompt
+        remove-item function:_OLD_VIRTUAL_PROMPT
+    }
 
-# Revert to original values
-if (Test-Path function:_OLD_VIRTUAL_PROMPT) {
-    copy-item function:_OLD_VIRTUAL_PROMPT function:prompt
-    remove-item function:_OLD_VIRTUAL_PROMPT
-}
+    if (Test-Path env:_OLD_VIRTUAL_PYTHONHOME) {
+        copy-item env:_OLD_VIRTUAL_PYTHONHOME env:PYTHONHOME
+        remove-item env:_OLD_VIRTUAL_PYTHONHOME
+    }
 
-if (Test-Path env:_OLD_VIRTUAL_PYTHONHOME) {
-    copy-item env:_OLD_VIRTUAL_PYTHONHOME env:PYTHONHOME
-    remove-item env:_OLD_VIRTUAL_PYTHONHOME
-}
+    if (Test-Path env:_OLD_VIRTUAL_PATH) {
+        copy-item env:_OLD_VIRTUAL_PATH env:PATH
+        remove-item env:_OLD_VIRTUAL_PATH
+    }
 
-if (Test-Path env:_OLD_VIRTUAL_PATH) {
-    copy-item env:_OLD_VIRTUAL_PATH env:PATH
-    remove-item env:_OLD_VIRTUAL_PATH
+    if (Test-Path env:VIRTUAL_ENV) {
+        remove-item env:VIRTUAL_ENV
+    }
+
+    if (!$NonDestructive) {
+        # Self destruct!
+        remove-item function:deactivate
+    }
 }
 
+deactivate -nondestructive
+
+$env:VIRTUAL_ENV="__VENV_DIR__"
+
 # Set the prompt to include the env name
+# Make sure _OLD_VIRTUAL_PROMPT is global
+function global:_OLD_VIRTUAL_PROMPT {""}
 copy-item function:prompt function:_OLD_VIRTUAL_PROMPT
-function prompt {
-    Write-Host -NoNewline -ForegroundColor Green '[__VENV_NAME__]'
+function global:prompt {
+    Write-Host -NoNewline -ForegroundColor Green '__VENV_NAME__'
     _OLD_VIRTUAL_PROMPT
 }
 

Lib/venv/scripts/nt/Deactivate.ps1

-# Revert to original values
-if (Test-Path function:_OLD_VIRTUAL_PROMPT) {
-    copy-item function:_OLD_VIRTUAL_PROMPT function:prompt
-    remove-item function:_OLD_VIRTUAL_PROMPT
-}
-
-if (Test-Path env:_OLD_VIRTUAL_PYTHONHOME) {
-    copy-item env:_OLD_VIRTUAL_PYTHONHOME env:PYTHONHOME
-    remove-item env:_OLD_VIRTUAL_PYTHONHOME
-}
-
-if (Test-Path env:_OLD_VIRTUAL_PATH) {
-    copy-item env:_OLD_VIRTUAL_PATH env:PATH
-    remove-item env:_OLD_VIRTUAL_PATH
-}
-
-if (Test-Path env:VIRTUAL_ENV) {
-    remove-item env:VIRTUAL_ENV
-}

Misc/NEWS

@@ -159,6 +159,9 @@ Core and Builtins
 Library
 -------
 
+- Issue #18479: Changed venv Activate.ps1 to make deactivate a function, and
+  removed Deactivate.ps1.
+
 - Issue #18480: Add missing call to PyType_Ready to the _elementtree extension.
 
 - Issue #17778: Fix test discovery for test_multiprocessing. (Patch by