Also check for NULs in environment variables

This check is necessary, because the underlying API only reads strings
until the first NUL.

1 files changed, 11 insertions, 4 deletions

diff --git a/src/libstd/sys/windows/mod.rs b/src/libstd/sys/windows/mod.rs
index 3f76218eafe..7e5342a3fd4 100644
--- a/src/libstd/sys/windows/mod.rs
+++ b/src/libstd/sys/windows/mod.rs
@@ -72,10 +72,17 @@ pub fn decode_error_kind(errno: i32) -> ErrorKind {
     }
 }
 
-fn to_utf16_os(s: &OsStr) -> Vec<u16> {
-    let mut v: Vec<_> = s.encode_wide().collect();
-    v.push(0);
-    v
+pub fn to_u16s<S: AsRef<OsStr>>(s: S) -> io::Result<Vec<u16>> {
+    fn inner(s: &OsStr) -> io::Result<Vec<u16>> {
+        let mut maybe_result: Vec<u16> = s.encode_wide().collect();
+        if maybe_result.iter().any(|&u| u == 0) {
+            return Err(io::Error::new(io::ErrorKind::InvalidInput,
+                                      "strings passed to WinAPI cannot contain NULs"));
+        }
+        maybe_result.push(0);
+        Ok(maybe_result)
+    }
+    inner(s.as_ref())
 }
 
 // Many Windows APIs follow a pattern of where we hand a buffer and then they