From b39c9e499c2f99d0fc0a6488d47cc815ada86c54 Mon Sep 17 00:00:00 2001
From: Niels Grewe <niels.grewe@halbordnung.de>
Date: Mon, 2 Dec 2019 23:25:35 +0100
Subject: [PATCH] fix a concurrency issue in NSArray enumeration test

---
 .travis.yml                 |  1 -
 Tests/base/NSArray/blocks.m | 20 +++++++++++++++++---
 2 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/.travis.yml b/.travis.yml
index 042c9088d..6d85c0b65 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -23,7 +23,6 @@ matrix:
           env: LIBRARY_COMBO=gnu-gnu-gnu
 sudo: required
 before_install:
-    - ls /usr/local/bin
     - sudo apt-get -qq update
     - sudo apt-get install -y cmake pkg-config libgnutls28-dev libgmp-dev libffi-dev libicu-dev libxml2-dev libxslt1-dev libssl-dev libavahi-client-dev zlib1g-dev libblocksruntime-dev
     - >
diff --git a/Tests/base/NSArray/blocks.m b/Tests/base/NSArray/blocks.m
index 9112e39d5..ec8a20a9b 100644
--- a/Tests/base/NSArray/blocks.m
+++ b/Tests/base/NSArray/blocks.m
@@ -4,10 +4,12 @@
 #import <Foundation/NSIndexSet.h>
 #import <Foundation/NSString.h>
 #import <Foundation/NSEnumerator.h>
+#import <Foundation/NSLock.h>
 #import <Foundation/NSValue.h>
 
 static NSUInteger fooCount = 0;
 static NSUInteger lastIndex = NSNotFound;
+static BOOL reverse = NO;
 int main()
 {
   START_SET("NSArray Blocks")
@@ -16,10 +18,20 @@ int main()
 # endif
 # if __has_feature(blocks)
   NSAutoreleasePool   *arp = [NSAutoreleasePool new];
-
+  NSLock *lock = [[[NSLock alloc] init] autorelease];
   NSArray *array = [NSArray arrayWithObjects: @"foo", @"bar", @"foo", nil];
-  void(^enumBlock)(id,NSUInteger,BOOL*) =  ^(id obj, NSUInteger index, BOOL *stop){
-    if ([obj isEqual: @"foo"]){ fooCount++;} lastIndex = index;};
+  void(^enumBlock)(id,NSUInteger,BOOL*) =  ^(id obj, NSUInteger index, BOOL *stop) {
+   [lock lock];
+   if ([obj isEqual: @"foo"]) {
+      fooCount++;
+    }
+    if (lastIndex == NSNotFound) {
+      lastIndex = index;
+    } else {
+      lastIndex = reverse ? MIN(lastIndex, index) : MAX(lastIndex, index);
+    }
+    [lock unlock];
+  };
   [array enumerateObjectsUsingBlock: enumBlock];
   PASS((2 == fooCount) && (lastIndex == 2),
        "Can forward enumerate array using a block");
@@ -31,9 +43,11 @@ int main()
        "Can forward enumerate array concurrently using a block");
   fooCount = 0;
   lastIndex = NSNotFound;
+  reverse = YES;
   [array enumerateObjectsWithOptions: NSEnumerationReverse
                           usingBlock: enumBlock];
   PASS((0 == lastIndex), "Can enumerate array in reverse using a block");
+  reverse = NO;
   fooCount = 0;
   lastIndex = NSNotFound;
   enumBlock = ^(id obj, NSUInteger index, BOOL *stop){if ([obj isEqual: @"foo"]){