From 320c4e31e124f99601399d00935362b587c77510 Mon Sep 17 00:00:00 2001
From: Thiago Macieira <thiago.macieira@intel.com>
Date: Tue, 25 Sep 2012 16:30:48 +0200
Subject: Make QContiguousCache with zero capacity not crash

These containers don't make sense and will just result in no action
being taken (all items added will simply be discarded), but it
shouldn't crash due to a division by zero.

Update the documentation to explain the fact.

Task-number: QTBUG-27339
Change-Id: Ib9acf5c0a9a826e6853e7beaf5e56511fde98dc6
Reviewed-by: Giuseppe D'Angelo <giuseppe.dangelo@kdab.com>
Reviewed-by: Ian Walters <ian@walters.id.au>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
---
 src/corelib/tools/qcontiguouscache.h | 6 ++++++
 1 file changed, 6 insertions(+)

(limited to 'src/corelib/tools/qcontiguouscache.h')

diff --git a/src/corelib/tools/qcontiguouscache.h b/src/corelib/tools/qcontiguouscache.h
index 8713a3407a..e1cc65f10a 100644
--- a/src/corelib/tools/qcontiguouscache.h
+++ b/src/corelib/tools/qcontiguouscache.h
@@ -341,6 +341,8 @@ void QContiguousCache<T>::freeData(Data *x)
 template <typename T>
 void QContiguousCache<T>::append(const T &value)
 {
+    if (!d->alloc)
+        return;     // zero capacity
     detach();
     if (QTypeInfo<T>::isComplex) {
         if (d->count == d->alloc)
@@ -362,6 +364,8 @@ void QContiguousCache<T>::append(const T &value)
 template<typename T>
 void QContiguousCache<T>::prepend(const T &value)
 {
+    if (!d->alloc)
+        return;     // zero capacity
     detach();
     if (d->start)
         d->start--;
@@ -385,6 +389,8 @@ template<typename T>
 void QContiguousCache<T>::insert(int pos, const T &value)
 {
     Q_ASSERT_X(pos >= 0 && pos < INT_MAX, "QContiguousCache<T>::insert", "index out of range");
+    if (!d->alloc)
+        return;     // zero capacity
     detach();
     if (containsIndex(pos)) {
         if (QTypeInfo<T>::isComplex) {
-- 
cgit v1.2.3