Index: nspr-4.8.6/mozilla/nsprpub/pr/src/md/unix/uxproces.c
===================================================================
--- nspr-4.8.6.orig/mozilla/nsprpub/pr/src/md/unix/uxproces.c
+++ nspr-4.8.6/mozilla/nsprpub/pr/src/md/unix/uxproces.c
@@ -60,6 +60,10 @@ PR_IMPORT_DATA(char **) environ;
 #define SA_RESTART 0
 #endif
 
+#ifndef ARRAY_SIZE
+#define ARRAY_SIZE(ra) (sizeof(ra)/sizeof((ra)[0]))
+#endif
+
 /*
  **********************************************************************
  *
@@ -457,6 +461,9 @@ _MD_CreateUnixProcess(
 #define NBUCKETS_LOG2 6
 #define NBUCKETS (1 << NBUCKETS_LOG2)
 #define PID_HASH_MASK ((pid_t) (NBUCKETS - 1))
+#define BITS_PER_CHAR 8
+#define MAX_PIDS 65535
+#define MAX_ENTRIES_PER_BUCKET (MAX_PIDS / NBUCKETS)
 
 static pr_PidRecord *
 CreatePidRecord(void)
@@ -631,14 +638,90 @@ static void WaitPidDaemonThread(void *un
 
 #else /* _PR_NATIVE_THREADS */
 
+// only accessed from WaitPidDaemonThread()
+static pid_t pr_wp_pids[MAX_ENTRIES_PER_BUCKET];
+
+static void WaitForPidsInArray(unsigned count)
+{
+    unsigned n;
+    pid_t pid;
+    int status;
+
+    for (n = 0; n < count; ++n) {
+	do {
+	    pid = waitpid(pr_wp_pids[n], &status, WNOHANG);
+	} while ((pid_t) -1 == pid && EINTR == errno);
+
+	if (pid == 0) /* still running */
+	    continue;
+
+	PR_ASSERT((pid_t) -1 != pid);
+
+	PR_Lock(pr_wp.ml);
+	ProcessReapedChildInternal(pid, status);
+	PR_Unlock(pr_wp.ml);
+    }
+}
+
+static void WaitForPidsInBucket(unsigned bucketIndex)
+{
+    pr_PidRecord *pRec = NULL;
+    unsigned count;
+    unsigned maxIteratorInvalidation = 2;
+
+    while (1)
+    {
+	count = 0;
+
+	PR_Lock(pr_wp.ml);
+
+	if (NULL == pRec) {
+	    pRec = pr_wp.pidTable[bucketIndex];
+	} else {
+	    // while unlocked, pRec could have been deleted.
+	    pr_PidRecord *pCur = pr_wp.pidTable[bucketIndex];
+	    while ((NULL != pCur) && (pCur != pRec)) {
+		pCur = pCur->next;
+	    }
+
+	    if (NULL == pCur) {
+		if (maxIteratorInvalidation > 0) {
+		    --maxIteratorInvalidation;
+		    pRec = pr_wp.pidTable[bucketIndex];
+		} else {
+		    pRec = NULL;
+		}
+	    }
+	    // else pRec was found and is still valid
+	}
+
+	while ((NULL != pRec) && (count < ARRAY_SIZE(pr_wp_pids))) {
+	    if (pRec->pid > 0 && (_PR_PID_REAPED != pRec->state)) {
+		pr_wp_pids[count] = pRec->pid;
+		++count;
+	    }
+	    pRec = pRec->next;
+	}
+
+	PR_Unlock(pr_wp.ml);
+
+	if (count == 0)
+	    break;
+
+	WaitForPidsInArray(count);
+
+	if (NULL == pRec)
+	    break;
+    }
+}
+
 static void WaitPidDaemonThread(void *unused)
 {
     PRPollDesc pd;
     PRFileDesc *fd;
     int rv;
     char ctmp;
-    pid_t pid;
-    int status;
+    unsigned bucket;
 #ifdef _PR_SHARE_CLONES
     struct pr_CreateProcOp *op;
 #endif
@@ -677,6 +760,18 @@ static void WaitPidDaemonThread(void *un
 		op->oserror = PR_GetOSError();
 	    }
 	    PR_Lock(pr_wp.ml);
+	    if (op->process) {
+		pr_PidRecord *pRec = FindPidTable(op->process->md.pid);
+		// If someone forgets to detach or wait for their process,
+		// the stale entry hangs around until the OS re-uses the PID
+		PR_ASSERT(NULL == pRec);
+		pRec = CreatePidRecord();
+		PR_ASSERT(pRec);
+		pRec->pid = op->process->md.pid;
+		pRec->state = _PR_PID_WAITING;
+		pRec->exitStatus = -1;
+		InsertPidTable(pRec);
+	    }
 	    pr_wp.opHead = op->next;
 	    if (NULL == pr_wp.opHead) {
 		pr_wp.opTail = NULL;
@@ -687,20 +782,8 @@ static void WaitPidDaemonThread(void *un
 	}
 #endif
 
-	while (1) {
-	    do {
-	        pid = waitpid((pid_t) -1, &status, WNOHANG);
-	    } while ((pid_t) -1 == pid && EINTR == errno);
-	    if (0 == pid) break;
-	    if ((pid_t) -1 == pid) {
-		/* must be because we have no child processes */
-		PR_ASSERT(ECHILD == errno);
-		break;
-            }
-
-	    PR_Lock(pr_wp.ml);
-            ProcessReapedChildInternal(pid, status);
-	    PR_Unlock(pr_wp.ml);
+	for (bucket = 0; bucket < NBUCKETS; ++bucket) {
+	    WaitForPidsInBucket(bucket);
 	}
     }
 }
@@ -825,13 +908,14 @@ PRStatus _MD_DetachUnixProcess(PRProcess
 	pRec->state = _PR_PID_DETACHED;
 	InsertPidTable(pRec);
     } else {
-	PR_ASSERT(_PR_PID_REAPED == pRec->state);
-	if (_PR_PID_REAPED != pRec->state) {
+	if (_PR_PID_WAITING == pRec->state) {
+	    pRec->state = _PR_PID_DETACHED;
+	} else if (_PR_PID_REAPED == pRec->state) {
+	    DeletePidTable(pRec);
+	    DeletePidRecord(pRec);
+	} else {
 	    PR_SetError(PR_INVALID_ARGUMENT_ERROR, 0);
 	    retVal = PR_FAILURE;
-	} else {
-        DeletePidTable(pRec);
-        DeletePidRecord(pRec);
 	}
     }
     PR_DELETE(process);
@@ -879,11 +963,32 @@ PRStatus _MD_WaitUnixProcess(
 	DeletePidTable(pRec);
 	DeletePidRecord(pRec);
     } else {
-	PR_ASSERT(_PR_PID_REAPED == pRec->state);
+	if (_PR_PID_WAITING == pRec->state)
+	{
+	    while (!interrupted && _PR_PID_REAPED != pRec->state) {
+		if (PR_WaitCondVar(pRec->reapedCV, PR_INTERVAL_NO_TIMEOUT) == PR_FAILURE
+		    && PR_GetError() == PR_PENDING_INTERRUPT_ERROR) {
+		    interrupted = PR_TRUE;
+		}
+	    }
+	} else if (_PR_PID_DETACHED == pRec->state) {
+	    PR_SetError(PR_INVALID_ARGUMENT_ERROR, 0);
+	    retVal = PR_FAILURE;
+	    goto done;
+	} else {
+	    PR_ASSERT(_PR_PID_REAPED == pRec->state);
+	}
+
+	if (_PR_PID_REAPED == pRec->state) {
+	    if (exitCode) {
+		*exitCode = pRec->exitStatus;
+	    }
+	} else if (retVal == PR_SUCCESS) {
+	    PR_ASSERT(interrupted);
+	    retVal = PR_FAILURE;
+	}
+
 	DeletePidTable(pRec);
-        if (exitCode) {
-            *exitCode = pRec->exitStatus;
-        }
 	DeletePidRecord(pRec);
     }
     PR_DELETE(process);