[ruby-core:32261] Re: [Ruby 1.9-Bug#3812][Open] (mswin|mingw) ENV[]= fails silently to set huge values

Hi,

At Fri, 10 Sep 2010 02:52:07 +0900,
Peter Weldon wrote in [ruby-core:32250]:
> On mswin&mingw the size of an environment key, value pair is
> bounded by _MAX_ENV. Calls to putenv() or _putenv() that
> exceed this will fail and not set the value.

Thank you, but alloca is not safe for such huge values.  IIRC,
it could return invalid address silently.


diff --git a/hash.c b/hash.c
index 8bba586..638f493 100644
--- a/hash.c
+++ b/hash.c
@@ -2139,28 +2139,24 @@ void
 ruby_setenv(const char *name, const char *value)
 {
 #if defined(_WIN32)
-    int len;
-    char *buf;
+    VALUE buf;
     if (strchr(name, '=')) {
+      fail:
 	errno = EINVAL;
 	rb_sys_fail("ruby_setenv");
     }
+    len = strlen(name) + 1 + 1;
     if (value) {
-	len = strlen(name) + 1 + strlen(value) + 1;
-	buf = ALLOCA_N(char, len);
-	snprintf(buf, len, "%s=%s", name, value);
-	putenv(buf);
-
-	/* putenv() doesn't handle empty value */
-	if (!*value)
-	    SetEnvironmentVariable(name,value);
+	buf = rb_sprintf("%s=%s", name, value);
     }
     else {
-	len = strlen(name) + 1 + 1;
-	buf = ALLOCA_N(char, len);
-	snprintf(buf, len, "%s=", name);
-	putenv(buf);
-	SetEnvironmentVariable(name, 0);
+	buf = rb_sprintf("%s=", name);
+    }
+    if (putenv(RSTRING_PTR(buf))) goto fail;
+    rb_str_resize(buf);
+    if (!value || !*value) {
+	/* putenv() doesn't handle empty value */
+	if (SetEnvironmentVariable(name,value)) goto fail;
     }
 #elif defined(HAVE_SETENV) && defined(HAVE_UNSETENV)
 #undef setenv


-- 
Nobu Nakada