=== modified file 'include/MemPool.h'
--- include/MemPool.h	2012-08-28 13:00:30 +0000
+++ include/MemPool.h	2013-01-12 22:12:27 +0000
@@ -204,7 +204,7 @@
     virtual char const *objectType() const;
     virtual size_t objectSize() const = 0;
     virtual int getInUseCount() = 0;
-    void zeroOnPush(bool doIt);
+    void zeroBlocks(bool doIt) {doZero = doIt;}
     int inUseCount();
 
     /**
@@ -226,7 +226,13 @@
     static size_t RoundedSize(size_t minSize);
 
 protected:
-    bool doZeroOnPush;
+    /** Whether to zero memory on initial allocation and on return to the pool.
+     *
+     * We do this on some pools because many object constructors are/were incomplete
+     * and we are afraid some code may use the object after free.
+     * These probems are becoming less common, so when possible set this to false.
+     */
+    bool doZero;
 
 private:
     const char *label;

=== modified file 'lib/MemPool.cc'
--- lib/MemPool.cc	2012-09-01 14:38:36 +0000
+++ lib/MemPool.cc	2013-01-12 22:13:05 +0000
@@ -324,7 +324,7 @@
     return pools_inuse;
 }
 
-MemAllocator::MemAllocator(char const *aLabel) : doZeroOnPush(true), label(aLabel)
+MemAllocator::MemAllocator(char const *aLabel) : doZero(true), label(aLabel)
 {
 }
 
@@ -445,12 +445,6 @@
     --MemPools::GetInstance().poolCount;
 }
 
-void
-MemAllocator::zeroOnPush(bool doIt)
-{
-    doZeroOnPush = doIt;
-}
-
 MemPoolMeter const &
 MemImplementingAllocator::getMeter() const
 {

=== modified file 'lib/MemPoolChunked.cc'
--- lib/MemPoolChunked.cc	2012-09-01 14:38:36 +0000
+++ lib/MemPoolChunked.cc	2013-01-12 22:01:58 +0000
@@ -141,7 +141,11 @@
     next = NULL;
     pool = aPool;
 
-    objCache = xcalloc(1, pool->chunk_size);
+    if (pool->doZero)
+        objCache = xcalloc(1, pool->chunk_size);
+    else
+        objCache = xmalloc(pool->chunk_size);
+
     freeList = objCache;
     void **Free = (void **)freeList;
 
@@ -196,7 +200,7 @@
      * not really need to be cleared.. There was a condition based on
      * the object size here, but such condition is not safe.
      */
-    if (doZeroOnPush)
+    if (doZero)
         memset(obj, 0, obj_size);
     Free = (void **)obj;
     *Free = freeCache;

=== modified file 'lib/MemPoolMalloc.cc'
--- lib/MemPoolMalloc.cc	2012-09-01 14:38:36 +0000
+++ lib/MemPoolMalloc.cc	2013-01-12 22:08:41 +0000
@@ -56,7 +56,10 @@
         memMeterDec(meter.idle);
         ++saved_calls;
     } else {
-        obj = xcalloc(1, obj_size);
+        if (doZero)
+            obj = xcalloc(1, obj_size);
+        else
+            obj = xmalloc(obj_size);
         memMeterInc(meter.alloc);
     }
     memMeterInc(meter.inuse);
@@ -71,7 +74,7 @@
         xfree(obj);
         memMeterDec(meter.alloc);
     } else {
-        if (doZeroOnPush)
+        if (doZero)
             memset(obj, 0, obj_size);
         memMeterInc(meter.idle);
         freelist.push_back(obj);

=== modified file 'src/Mem.h'
--- src/Mem.h	2012-09-21 14:57:30 +0000
+++ src/Mem.h	2013-01-12 22:38:36 +0000
@@ -75,7 +75,7 @@
 void memFreeBuf(size_t size, void *);
 FREE *memFreeBufFunc(size_t size);
 int memInUse(mem_type);
-void memDataInit(mem_type, const char *, size_t, int, bool zeroOnPush = true);
+void memDataInit(mem_type, const char *, size_t, int, bool doZero = true);
 void memCheckInit(void);
 void memConfigure(void);
 

=== modified file 'src/mem.cc'
--- src/mem.cc	2012-10-04 09:14:06 +0000
+++ src/mem.cc	2013-01-12 22:36:35 +0000
@@ -201,7 +201,7 @@
  * Relies on Mem::Init() having been called beforehand.
  */
 void
-memDataInit(mem_type type, const char *name, size_t size, int max_pages_notused, bool zeroOnPush)
+memDataInit(mem_type type, const char *name, size_t size, int max_pages_notused, bool doZero)
 {
     assert(name && size);
 
@@ -209,7 +209,7 @@
         return;
 
     MemPools[type] = memPoolCreate(name, size);
-    MemPools[type]->zeroOnPush(zeroOnPush);
+    MemPools[type]->zeroBlocks(doZero);
 }
 
 /* find appropriate pool and use it (pools always init buffer with 0s) */
@@ -477,7 +477,7 @@
     /** Lastly init the string pools. */
     for (i = 0; i < mem_str_pool_count; ++i) {
         StrPools[i].pool = memPoolCreate(StrPoolsAttrs[i].name, StrPoolsAttrs[i].obj_size);
-        StrPools[i].pool->zeroOnPush(false);
+        StrPools[i].pool->zeroBlocks(false);
 
         if (StrPools[i].pool->objectSize() != StrPoolsAttrs[i].obj_size)
             debugs(13, DBG_IMPORTANT, "Notice: " << StrPoolsAttrs[i].name << " is " << StrPools[i].pool->objectSize() << " bytes instead of requested " << StrPoolsAttrs[i].obj_size << " bytes");