From 9fc98788e4fb1ea1f330d44c8b2019b3fe6444f7 Mon Sep 17 00:00:00 2001
From: Ron Yorston <rmy@pobox.com>
Date: Fri, 3 Jul 2015 14:12:47 +0100
Subject: Allow different ways to manipulate environment for XP vs 64-bit

Commit fa147bd 'Use putenv to implement unsetenv/clearenv' allowed
BusyBox to run on ReactOS but broke it on Windows XP so it was
reverted.

It turns out that the same change is required on 64-bit Windows.
Reinstate the 'safe' environment manipulation code but make it a
configuration option.  Add a config file for 64-bit Windows that
does the right thing.
---
 win32/env.c | 59 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 59 insertions(+)

(limited to 'win32')

diff --git a/win32/env.c b/win32/env.c
index f8d231a8f..48b86c555 100644
--- a/win32/env.c
+++ b/win32/env.c
@@ -104,12 +104,70 @@ char **env_setenv(char **env, const char *name)
 		else {
 			for (; env[i]; i++)
 				env[i] = env[i+1];
+#if !ENABLE_SAFE_ENV
 			SetEnvironmentVariable(name, NULL);
+#endif
 		}
 	}
 	return env;
 }
 
+#if ENABLE_SAFE_ENV
+/*
+ * Removing an environment variable with WIN32 putenv requires an argument
+ * like "NAME="; glibc omits the '='.  The implementations of unsetenv and
+ * clearenv allow for this.
+ *
+ * It isn't possible to create an environment variable with an empty value
+ * using WIN32 putenv.
+ */
+#undef putenv
+int unsetenv(const char *env)
+{
+	char *name;
+	int ret;
+
+	name = xmalloc(strlen(env)+2);
+	strcat(strcpy(name, env), "=");
+	ret = putenv(name);
+	free(name);
+
+	return ret;
+}
+
+int clearenv(void)
+{
+	char *name, *s;
+
+	while ( environ && *environ ) {
+		if ( (s=strchr(*environ, '=')) != NULL ) {
+			name = xstrndup(*environ, s-*environ+1);
+			putenv(name);
+			free(name);
+		}
+		else {
+			return -1;
+		}
+	}
+	return 0;
+}
+
+int mingw_putenv(const char *env)
+{
+	char *s;
+
+	if ( (s=strchr(env, '=')) == NULL ) {
+		return unsetenv(env);
+	}
+
+	if ( s[1] != '\0' ) {
+		return putenv(env);
+	}
+
+	/* can't set empty value */
+	return 0;
+}
+#else
 void unsetenv(const char *env)
 {
 	env_setenv(environ, env);
@@ -128,3 +186,4 @@ int clearenv(void)
 	environ = NULL;
 	return 0;
 }
+#endif
-- 
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