relanding fix for bug 317278 :-(

git-svn-id: svn://10.0.0.236/trunk@201179 18797224-902f-48f8-a5cc-f745e15eee43

mozilla/layout/generic/nsLineBox.cpp

@@ -875,14 +875,20 @@ nsFloatCacheList::nsFloatCacheList() :
 
 nsFloatCacheList::~nsFloatCacheList()
 {
-  nsFloatCache* fc = mHead;
-  while (fc) {
-    nsFloatCache* next = fc->mNext;
-    delete fc;
-    fc = next;
+  DeleteAll();
+  MOZ_COUNT_DTOR(nsFloatCacheList);
+}
+
+void
+nsFloatCacheList::DeleteAll()
+{
+  nsFloatCache* c = mHead;
+  while (c) {
+    nsFloatCache* next = c->Next();
+    delete c;
+    c = next;
   }
   mHead = nsnull;
-  MOZ_COUNT_DTOR(nsFloatCacheList);
 }
 
 nsFloatCache*
@@ -929,17 +935,24 @@ nsFloatCacheList::Find(nsIFrame* aOutOfFlowFrame)
   return fc;
 }
 
-void
-nsFloatCacheList::Remove(nsFloatCache* aElement)
+nsFloatCache*
+nsFloatCacheList::RemoveAndReturnPrev(nsFloatCache* aElement)
 {
-  nsFloatCache** fcp = &mHead;
-  nsFloatCache* fc;
-  while (nsnull != (fc = *fcp)) {
+  NS_ASSERTION(!aElement->mNext, "Can only remove a singleton element");
+
+  nsFloatCache* fc = mHead;
+  nsFloatCache* prev = nsnull;
+  while (fc) {
     if (fc == aElement) {
-      *fcp = fc->mNext;
-      break;
+      if (prev) {
+        prev->mNext = fc->mNext;
+      } else {
+        mHead = fc->mNext;
+      }
+      return prev;
     }
-    fcp = &fc->mNext;
+    prev = fc;
+    fc = fc->mNext;
   }
 }
 
@@ -975,6 +988,22 @@ nsFloatCacheFreeList::Append(nsFloatCacheList& aList)
   aList.mHead = nsnull;
 }
 
+void
+nsFloatCacheFreeList::Remove(nsFloatCache* aElement)
+{
+  nsFloatCache* prev = nsFloatCacheList::RemoveAndReturnPrev(aElement);
+  if (mTail == aElement) {
+    mTail = prev;
+  }
+}
+
+void
+nsFloatCacheFreeList::DeleteAll()
+{
+  nsFloatCacheList::DeleteAll();
+  mTail = nsnull;
+}
+
 nsFloatCache*
 nsFloatCacheFreeList::Alloc()
 {