From: Alex Rousskov <rousskov@measurement-factory.com>
Date: Tue, 12 Apr 2011 22:02:13 +0000 (-0600)
Subject: Fixed Ipc::Mem::PageStack::theSize type to be signed.
X-Git-Tag: take06~39
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e963b5b5d578ffd2e7b96cd87d8150c36bb78eae;p=thirdparty%2Fsquid.git

Fixed Ipc::Mem::PageStack::theSize type to be signed.
Otherwise, unsigned zero theSize underflows in pop(), causing an infinite loop.
---

diff --git a/src/ipc/mem/PageStack.cc b/src/ipc/mem/PageStack.cc
index a31d774f2b..41b09967c1 100644
--- a/src/ipc/mem/PageStack.cc
+++ b/src/ipc/mem/PageStack.cc
@@ -71,7 +71,7 @@ void
 Ipc::Mem::PageStack::push(const Value value)
 {
     Must(value != Writable);
-    Must(value <= shared->theCapacity);
+    Must(static_cast<Offset>(value) <= shared->theCapacity);
     // find a Writable slot, starting with theFirstWritable and going right
     while (shared->theSize < shared->theCapacity) {
         const Offset idx = shared->theFirstWritable;
diff --git a/src/ipc/mem/PageStack.h b/src/ipc/mem/PageStack.h
index d7a8bd7fe9..3048ba20a3 100644
--- a/src/ipc/mem/PageStack.h
+++ b/src/ipc/mem/PageStack.h
@@ -31,7 +31,8 @@ public:
     void push(const Value value);
 
 private:
-    typedef unsigned int Offset; ///< stack index type
+    /// stack index and size type (may temporary go negative)
+    typedef int Offset;
 
     struct Shared {
         Shared(const unsigned int aCapacity);