Add test case for #893, prepare for 4-digit issue numbers

893/README

@@ -0,0 +1,8 @@
+Compile libzmq with this configure options: configure --with-poller=select
+
+Then compile the test case normally:
+
+g++ -o issue issue.c -lzmq -lpthread
+
+The problem happens under Cygwin for n = 28, but not for n = 27:
+the test hangs in the zmq_ctx_destroy() call.

893/issue.c

@@ -0,0 +1,53 @@
+#include <assert.h>
+#include <zmq.h>
+
+#define n 28  /* n = 27 works */
+#define m n
+
+int main(void)
+{
+    void* ctx;
+    void* sckts[n];
+    int rc;
+    int i;
+
+    assert(m <= n);
+
+    printf("#       : create context\n");
+    ctx = zmq_ctx_new();
+    assert(ctx);
+
+    rc = zmq_ctx_get(ctx, ZMQ_MAX_SOCKETS);
+    assert(rc >= n);
+
+    printf("##      : starting to create sockets\n");
+    for(i=0; i<n; ++i) {
+        if(i == 0)
+            sckts[i] = zmq_socket(ctx, ZMQ_REP);
+        else
+            sckts[i] = zmq_socket(ctx, ZMQ_REQ);
+        assert(sckts[i]);
+    }
+
+    printf("####    : starting to connect sockets\n");
+    for(i=0; i<m; ++i) {
+        if(i == 0)
+            rc = zmq_bind(sckts[i], "inproc://test");
+        else
+            rc = zmq_connect(sckts[i], "inproc://test");
+        assert(rc == 0);
+    }
+
+    printf("######  : starting to close sockets\n");
+    for(i=0; i<n; ++i) {
+        rc = zmq_close(sckts[i]);
+        assert(rc == 0);
+    }
+
+    printf("####### : destroy context\n");
+    rc = zmq_ctx_destroy(ctx);
+    assert(rc == 0);
+
+    printf("Success : all resources released\n");
+    return 0;
+}

README

@@ -1,6 +1,6 @@
 This is the git repo for issue test cases
 
-Each issue has a subdirectory named 'nnn' where that is the issue number.
+Each issue has a subdirectory named 'nnn' or 'nnnn' where that is the issue number.
 
 Within that subdirectory, there should directories 2-1 and 3-0 for version-specific test cases.