[3461] Corrected valgrind errors in the util library.

src/lib/util/io/fd_share.cc

@@ -111,7 +111,9 @@ recv_fd(const int sock) {
     // one returned previously, even if that one is not closed yet. So,
     // we just re-number every one we get, so they are unique.
     int new_fd(dup(fd));
-    int close_error(close(fd));
+    // Only call close() if the descriptor is valid. Otherwise return
+    // an error.
+    int close_error(fd >=0 ? close(fd) : -1);
     if (close_error == -1 || new_fd == -1) {
         // We need to return an error, because something failed. But in case
         // it was the previous close, we at least try to close the duped FD.

src/lib/util/tests/memory_segment_local_unittest.cc

@@ -59,7 +59,12 @@ TEST(MemorySegmentLocal, TestLocal) {
 TEST(MemorySegmentLocal, TestTooMuchMemory) {
     auto_ptr<MemorySegment> segment(new MemorySegmentLocal());
 
-    EXPECT_THROW(segment->allocate(ULONG_MAX), bad_alloc);
+    // Although it should be perfectly fine to use the ULONG_MAX
+    // instead of LONG_MAX as the size_t value should be unsigned,
+    // Valgrind appears to be using the signed value and hence the
+    // maximum positive value is LONG_MAX for Valgrind. But, this
+    // should be sufficient to test the "too much memory" conditions.
+    EXPECT_THROW(segment->allocate(LONG_MAX), bad_alloc);
 }
 
 TEST(MemorySegmentLocal, TestBadDeallocate) {