From eebf12bec5c0999adf9d898a7a78b9fc3d2367ca Mon Sep 17 00:00:00 2001
From: Jeremy Soller <jackpot51@gmail.com>
Date: Sun, 29 Oct 2017 15:41:59 -0600
Subject: [PATCH] Fix returning too many errors from waitpid

---
 src/syscall/process.rs | 19 +++++++++++--------
 1 file changed, 11 insertions(+), 8 deletions(-)

diff --git a/src/syscall/process.rs b/src/syscall/process.rs
index 98e3034..d396be2 100644
--- a/src/syscall/process.rs
+++ b/src/syscall/process.rs
@@ -1160,17 +1160,20 @@ pub fn waitpid(pid: ContextId, status_ptr: usize, flags: usize) -> Result<Contex
     } else {
         let status = {
             let contexts = context::contexts();
-            let context_lock = contexts.get(pid).ok_or(Error::new(ECHILD))?;
-            let mut context = context_lock.write();
-            if context.ppid != ppid {
-                println!("Hack for rustc - changing ppid of {} from {} to {}", context.id.into(), context.ppid.into(), ppid.into());
-                context.ppid = ppid;
-                //return Err(Error::new(ECHILD));
+            if let Some(context_lock) = contexts.get(pid) {
+                let mut context = context_lock.write();
+                if context.ppid != ppid {
+                    println!("Hack for rustc - changing ppid of {} from {} to {}", context.id.into(), context.ppid.into(), ppid.into());
+                    context.ppid = ppid;
+                    //return Err(Error::new(ECHILD));
+                }
+                Some(context.status.clone())
+            } else {
+                None
             }
-            context.status.clone()
         };
 
-        if let context::Status::Exited(status) = status {
+        if let Some(context::Status::Exited(status)) = status {
             status_slice[0] = status;
             reap(pid)
         } else if flags & WNOHANG == WNOHANG {