[Issue 13916] Nested std.concurrency.receive doesn't work correctly

[d-bugmail at puremagic.com]

https://issues.dlang.org/show_bug.cgi?id=13916

Seb <greensunny12 at gmail.com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |greensunny12 at gmail.com

--- Comment #2 from Seb <greensunny12 at gmail.com> ---
So I experimented with removing the message from the list before the handler is
called, but I always get a LinkTerminated Exception which comes from the child
being terminated.
The child is in a while(true) loop, so it shouldn't get terminated, but for
some reason now its module deconstructor is now immediately called :/


diff --git a/std/concurrency.d b/std/concurrency.d
index 0e1b505bc..1c426bcc0 100644
--- a/std/concurrency.d
+++ b/std/concurrency.d
@@ -1974,8 +1980,9 @@ private
                 enum timedWait = false;
             }

-            bool onStandardMsg(ref Message msg)
+            bool onStandardMsg(ref Message msg, void delegate() beforeSuccess
= (){})
             {
                 foreach (i, t; Ops)
                 {
                     alias Args = Parameters!(t);
@@ -1985,10 +1992,13 @@ private
                     {
                         static if (is(ReturnType!(t) == bool))
                         {
-                            return msg.map(op);
+                            beforeSuccess();
+                            auto b = msg.map(op);
+                            return b;
                         }
                         else
                         {
+                            beforeSuccess();
                             msg.map(op);
                             return true;
                         }
@@ -2043,6 +2053,8 @@ private
             {
                 for (auto range = list[]; !range.empty;)
                 {
+                    import std.stdio;
+                    writefln("range: %s", range.front);
                     // Only the message handler will throw, so if this occurs
                     // we can be certain that the message was handled.
                     scope (failure)
@@ -2071,11 +2083,9 @@ private
                     }
                     else
                     {
-                        if (onStandardMsg(range.front))
-                        {
-                            list.removeAt(range);
+                        if (onStandardMsg(range.front, (){
list.removeAt(range); }))
                             return true;
-                        }
+
                         range.popFront();
                         continue;
                     }
```

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