From: Mukund Sivaraman <muks@isc.org>
Date: Thu, 12 Jul 2012 08:15:49 +0000 (+0530)
Subject: [2088] Handle NULL deallocate as a nop
X-Git-Tag: trac2351_base~188^2^2~3
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=25cc38bbd45cca618c0f073b743882865ebc1d64;p=thirdparty%2Fkea.git

[2088] Handle NULL deallocate as a nop
---

diff --git a/src/lib/util/memory_segment_local.cc b/src/lib/util/memory_segment_local.cc
index 468c499270..9c345c9040 100644
--- a/src/lib/util/memory_segment_local.cc
+++ b/src/lib/util/memory_segment_local.cc
@@ -31,6 +31,12 @@ MemorySegmentLocal::allocate(size_t size) {
 
 void
 MemorySegmentLocal::deallocate(void* ptr, size_t size) {
+    if (ptr == NULL) {
+        // Return early if NULL is passed to be deallocated (without
+        // modifying allocated_size, or comparing against it).
+        return;
+    }
+
     if (size > allocated_size_) {
       isc_throw(OutOfRange, "Invalid size to deallocate: " << size
                 << "; currently allocated size: " << allocated_size_);
diff --git a/src/lib/util/tests/memory_segment_local_unittest.cc b/src/lib/util/tests/memory_segment_local_unittest.cc
index e8ee1104d6..08787ad1e0 100644
--- a/src/lib/util/tests/memory_segment_local_unittest.cc
+++ b/src/lib/util/tests/memory_segment_local_unittest.cc
@@ -86,4 +86,17 @@ TEST(MemorySegmentLocal, TestBadDeallocate) {
     EXPECT_THROW(segment->deallocate(ptr, 2048), isc::OutOfRange);
 }
 
+TEST(MemorySegmentLocal, TestNullDeallocate) {
+    auto_ptr<MemorySegment> segment(new MemorySegmentLocal());
+
+    // By default, nothing is allocated.
+    EXPECT_TRUE(segment->allMemoryDeallocated());
+
+    // NULL deallocation is a no-op.
+    EXPECT_NO_THROW(segment->deallocate(NULL, 1024));
+
+    // This should still return true.
+    EXPECT_TRUE(segment->allMemoryDeallocated());
+}
+
 } // anonymous namespace