bpo-40280: Emscripten defaults to --with-ensurepip=no

Reduces installation size of browser bundle

Signed-off-by: Christian Heimes <christian@python.org>

Author: tiran

configure

@@ -20268,7 +20268,15 @@ $as_echo_n "checking for ensurepip... " >&6; }
 if test "${with_ensurepip+set}" = set; then :
   withval=$with_ensurepip;
 else
-  with_ensurepip=upgrade
+
+      case $ac_sys_system in #(
+  Emscripten) :
+    $with_ensurepip=no ;; #(
+  *) :
+    with_ensurepip=upgrade
+       ;;
+esac
+
 fi
 
 case $with_ensurepip in #(

configure.ac

@@ -5871,7 +5871,12 @@ AC_ARG_WITH(ensurepip,
     [AS_HELP_STRING([--with-ensurepip@<:@=install|upgrade|no@:>@],
         ["install" or "upgrade" using bundled pip (default is upgrade)])],
     [],
-    [with_ensurepip=upgrade])
+    [
+      AS_CASE([$ac_sys_system],
+        [Emscripten], [$with_ensurepip=no],
+        [with_ensurepip=upgrade]
+      )
+    ])
 AS_CASE($with_ensurepip,
     [yes|upgrade],[ENSUREPIP=upgrade],
     [install],[ENSUREPIP=install],