[Issue 17760] New: catch block fails to catch Exception subclass when another Exception is in transit

[via Digitalmars-d-bugs]

https://issues.dlang.org/show_bug.cgi?id=17760

          Issue ID: 17760
           Summary: catch block fails to catch Exception subclass when
                    another Exception is in transit
           Product: D
           Version: D2
          Hardware: x86_64
                OS: Linux
            Status: NEW
          Severity: normal
          Priority: P1
         Component: druntime
          Assignee: nob...@puremagic.com
          Reporter: hst...@quickfur.ath.cx

Code:
---------
import std.stdio;
class MyException : Exception
{
    this() { super("MYMY"); }
}
struct S
{
    ~this()
    {
        try { throw new MyException; }
        catch(MyException e) { writefln("Collected MyException: %s", e.msg); }
        catch(Exception e)   { writefln("Collected Exception: %s",   e.msg); }
    }
    void method() { throw new Exception("Dumb error"); }
}
void main()
{
    try {
        S s;
        s.method();
    } catch(Exception) {}
}
---------

Expected output:
---------
Collected MyException: MYMY
---------

Actual output:
---------
Collected Exception: MYMY
---------

This appears to happen only when another Exception is in transit. If S is
destructed normally at the end of the block rather than as part of exception
winding (e.g., if the call to s.method() is commented out), the catch block
works as expected.

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