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-rw-r--r--libqpdf/NNTree.cc96
-rw-r--r--libqpdf/QPDF.cc2
-rw-r--r--libqpdf/QPDFNameTreeObjectHelper.cc33
-rw-r--r--libqpdf/QPDFNumberTreeObjectHelper.cc41
-rw-r--r--libqpdf/qpdf/NNTree.hh7
5 files changed, 142 insertions, 37 deletions
diff --git a/libqpdf/NNTree.cc b/libqpdf/NNTree.cc
index 4f9ddcce..61710032 100644
--- a/libqpdf/NNTree.cc
+++ b/libqpdf/NNTree.cc
@@ -50,6 +50,57 @@ NNTreeIterator::NNTreeIterator(NNTreeImpl& impl) :
{
}
+void
+NNTreeIterator::updateIValue(bool allow_invalid)
+{
+ // ivalue should never be used inside the class since we return a
+ // pointer/reference to it. Every bit of code that ever changes
+ // what object the iterator points to should take care to call
+ // updateIValue. Failure to do this means that any old references
+ // to *iter will point to incorrect objects, though the next
+ // dereference of the iterator will fix it. This isn't necessarily
+ // catastrophic, but it would be confusing. The test suite
+ // attempts to exercise various cases to ensure we don't introduce
+ // that bug in the future, but sadly it's tricky to verify by
+ // reasoning about the code that this constraint is always
+ // satisfied. Whenever we update what the iterator points to, we
+ // should call setItemNumber, which calls this. If we change what
+ // the iterator in some other way, such as replacing a value or
+ // removing an item and making the iterator point at a different
+ // item in potentially the same position, we must call
+ // updateIValue as well. These cases are handled, and for good
+ // measure, we also call updateIValue in operator* and operator->.
+
+ bool okay = false;
+ if ((item_number >= 0) &&
+ this->node.isInitialized() &&
+ this->node.isDictionary())
+ {
+ auto items = this->node.getKey(impl.details.itemsKey());
+ if (this->item_number + 1 < items.getArrayNItems())
+ {
+ okay = true;
+ this->ivalue.first = items.getArrayItem(this->item_number);
+ this->ivalue.second = items.getArrayItem(1+this->item_number);
+ }
+ else
+ {
+ error(impl.qpdf, node, "update ivalue: items array is too short");
+ }
+ }
+ if (! okay)
+ {
+ if (! allow_invalid)
+ {
+ throw std::logic_error(
+ "attempt made to dereference an invalid"
+ " name/number tree iterator");
+ }
+ this->ivalue.first = QPDFObjectHandle();
+ this->ivalue.second = QPDFObjectHandle();
+ }
+}
+
NNTreeIterator::PathElement::PathElement(
QPDFObjectHandle const& node, int kid_number) :
node(node),
@@ -522,6 +573,7 @@ NNTreeIterator::remove()
// We don't have to do anything since the removed item's
// successor now occupies its former location.
QTC::TC("qpdf", "NNTree erased non-last item");
+ updateIValue();
}
else
{
@@ -630,19 +682,15 @@ NNTreeIterator::operator--()
NNTreeIterator::reference
NNTreeIterator::operator*()
{
- if (this->item_number < 0)
- {
- throw std::logic_error(
- "attempt made to dereference an invalid"
- " name/number tree iterator");
- }
- auto items = this->node.getKey(impl.details.itemsKey());
- if (items.getArrayNItems() < this->item_number + 2)
- {
- error(impl.qpdf, node, "operator*: items array is too short");
- }
- return std::make_pair(items.getArrayItem(this->item_number),
- items.getArrayItem(1+this->item_number));
+ updateIValue(false);
+ return this->ivalue;
+}
+
+NNTreeIterator::pointer
+NNTreeIterator::operator->()
+{
+ updateIValue(false);
+ return &(this->ivalue);
}
bool
@@ -660,7 +708,7 @@ NNTreeIterator::operator==(NNTreeIterator const& other) const
auto opi = other.path.begin();
while (tpi != this->path.end())
{
- if ((*tpi).kid_number != (*opi).kid_number)
+ if (tpi->kid_number != opi->kid_number)
{
return false;
}
@@ -679,6 +727,7 @@ NNTreeIterator::setItemNumber(QPDFObjectHandle const& node, int n)
{
this->node = node;
this->item_number = n;
+ updateIValue();
}
void
@@ -961,7 +1010,7 @@ NNTreeImpl::repair()
auto new_node = QPDFObjectHandle::newDictionary();
new_node.replaceKey(details.itemsKey(), QPDFObjectHandle::newArray());
NNTreeImpl repl(details, qpdf, new_node, false);
- for (auto i: *this)
+ for (auto const& i: *this)
{
repl.insert(i.first, i.second);
}
@@ -1005,15 +1054,15 @@ NNTreeImpl::findInternal(QPDFObjectHandle key, bool return_prev_if_not_found)
return end();
}
else if (first_item.valid() &&
- details.keyValid((*first_item).first) &&
- details.compareKeys(key, (*first_item).first) < 0)
+ details.keyValid(first_item->first) &&
+ details.compareKeys(key, first_item->first) < 0)
{
// Before the first key
return end();
}
else if (last_item.valid() &&
- details.keyValid((*last_item).first) &&
- details.compareKeys(key, (*last_item).first) > 0)
+ details.keyValid(last_item->first) &&
+ details.compareKeys(key, last_item->first) > 0)
{
// After the last key
if (return_prev_if_not_found)
@@ -1097,10 +1146,10 @@ NNTreeImpl::insertFirst(QPDFObjectHandle key, QPDFObjectHandle value)
}
items.insertItem(0, key);
items.insertItem(1, value);
- iter.item_number = 0;
+ iter.setItemNumber(iter.node, 0);
iter.resetLimits(iter.node, iter.lastPathElement());
iter.split(iter.node, iter.lastPathElement());
- return begin();
+ return iter;
}
NNTreeImpl::iterator
@@ -1112,11 +1161,12 @@ NNTreeImpl::insert(QPDFObjectHandle key, QPDFObjectHandle value)
QTC::TC("qpdf", "NNTree insert inserts first");
return insertFirst(key, value);
}
- else if (details.compareKeys(key, (*iter).first) == 0)
+ else if (details.compareKeys(key, iter->first) == 0)
{
QTC::TC("qpdf", "NNTree insert replaces");
auto items = iter.node.getKey(details.itemsKey());
items.setArrayItem(iter.item_number + 1, value);
+ iter.updateIValue();
}
else
{
@@ -1137,7 +1187,7 @@ NNTreeImpl::remove(QPDFObjectHandle key, QPDFObjectHandle* value)
}
if (value)
{
- *value = (*iter).second;
+ *value = iter->second;
}
iter.remove();
return true;
diff --git a/libqpdf/QPDF.cc b/libqpdf/QPDF.cc
index bb9b511d..f690d30a 100644
--- a/libqpdf/QPDF.cc
+++ b/libqpdf/QPDF.cc
@@ -3011,7 +3011,7 @@ QPDF::findAttachmentStreams()
return;
}
QPDFNameTreeObjectHelper ef_tree(embedded_files, *this);
- for (auto i: ef_tree)
+ for (auto const& i: ef_tree)
{
QPDFObjectHandle item = i.second;
if (item.isDictionary() &&
diff --git a/libqpdf/QPDFNameTreeObjectHelper.cc b/libqpdf/QPDFNameTreeObjectHelper.cc
index 7abc761a..1dc7f205 100644
--- a/libqpdf/QPDFNameTreeObjectHelper.cc
+++ b/libqpdf/QPDFNameTreeObjectHelper.cc
@@ -79,6 +79,7 @@ QPDFNameTreeObjectHelper::iterator&
QPDFNameTreeObjectHelper::iterator::operator++()
{
++(*impl);
+ updateIValue();
return *this;
}
@@ -86,14 +87,38 @@ QPDFNameTreeObjectHelper::iterator&
QPDFNameTreeObjectHelper::iterator::operator--()
{
--(*impl);
+ updateIValue();
return *this;
}
+void
+QPDFNameTreeObjectHelper::iterator::updateIValue()
+{
+ if (impl->valid())
+ {
+ auto p = *impl;
+ this->ivalue.first = p->first.getUTF8Value();
+ this->ivalue.second = p->second;
+ }
+ else
+ {
+ this->ivalue.first = "";
+ this->ivalue.second = QPDFObjectHandle();
+ }
+}
+
QPDFNameTreeObjectHelper::iterator::reference
QPDFNameTreeObjectHelper::iterator::operator*()
{
- auto p = **impl;
- return std::make_pair(p.first.getUTF8Value(), p.second);
+ updateIValue();
+ return this->ivalue;
+}
+
+QPDFNameTreeObjectHelper::iterator::pointer
+QPDFNameTreeObjectHelper::iterator::operator->()
+{
+ updateIValue();
+ return &this->ivalue;
}
bool
@@ -107,12 +132,14 @@ QPDFNameTreeObjectHelper::iterator::insertAfter(
std::string const& key, QPDFObjectHandle value)
{
impl->insertAfter(QPDFObjectHandle::newUnicodeString(key), value);
+ updateIValue();
}
void
QPDFNameTreeObjectHelper::iterator::remove()
{
impl->remove();
+ updateIValue();
}
QPDFNameTreeObjectHelper::iterator
@@ -175,7 +202,7 @@ QPDFNameTreeObjectHelper::findObject(
{
return false;
}
- oh = (*i).second;
+ oh = i->second;
return true;
}
diff --git a/libqpdf/QPDFNumberTreeObjectHelper.cc b/libqpdf/QPDFNumberTreeObjectHelper.cc
index 426891e2..a66a5f48 100644
--- a/libqpdf/QPDFNumberTreeObjectHelper.cc
+++ b/libqpdf/QPDFNumberTreeObjectHelper.cc
@@ -75,6 +75,7 @@ QPDFNumberTreeObjectHelper::iterator&
QPDFNumberTreeObjectHelper::iterator::operator++()
{
++(*impl);
+ updateIValue();
return *this;
}
@@ -82,14 +83,38 @@ QPDFNumberTreeObjectHelper::iterator&
QPDFNumberTreeObjectHelper::iterator::operator--()
{
--(*impl);
+ updateIValue();
return *this;
}
+void
+QPDFNumberTreeObjectHelper::iterator::updateIValue()
+{
+ if (impl->valid())
+ {
+ auto p = *impl;
+ this->ivalue.first = p->first.getIntValue();
+ this->ivalue.second = p->second;
+ }
+ else
+ {
+ this->ivalue.first = 0;
+ this->ivalue.second = QPDFObjectHandle();
+ }
+}
+
QPDFNumberTreeObjectHelper::iterator::reference
QPDFNumberTreeObjectHelper::iterator::operator*()
{
- auto p = **impl;
- return std::make_pair(p.first.getIntValue(), p.second);
+ updateIValue();
+ return this->ivalue;
+}
+
+QPDFNumberTreeObjectHelper::iterator::pointer
+QPDFNumberTreeObjectHelper::iterator::operator->()
+{
+ updateIValue();
+ return &this->ivalue;
}
bool
@@ -103,12 +128,14 @@ QPDFNumberTreeObjectHelper::iterator::insertAfter(
numtree_number key, QPDFObjectHandle value)
{
impl->insertAfter(QPDFObjectHandle::newInteger(key), value);
+ updateIValue();
}
void
QPDFNumberTreeObjectHelper::iterator::remove()
{
impl->remove();
+ updateIValue();
}
QPDFNumberTreeObjectHelper::iterator
@@ -162,7 +189,7 @@ QPDFNumberTreeObjectHelper::getMin()
{
return 0;
}
- return (*i).first;
+ return i->first;
}
QPDFNumberTreeObjectHelper::numtree_number
@@ -173,7 +200,7 @@ QPDFNumberTreeObjectHelper::getMax()
{
return 0;
}
- return (*i).first;
+ return i->first;
}
bool
@@ -192,7 +219,7 @@ QPDFNumberTreeObjectHelper::findObject(
{
return false;
}
- oh = (*i).second;
+ oh = i->second;
return true;
}
@@ -206,8 +233,8 @@ QPDFNumberTreeObjectHelper::findObjectAtOrBelow(
{
return false;
}
- oh = (*i).second;
- offset = idx - (*i).first;
+ oh = i->second;
+ offset = idx - i->first;
return true;
}
diff --git a/libqpdf/qpdf/NNTree.hh b/libqpdf/qpdf/NNTree.hh
index e8360df1..4a843a73 100644
--- a/libqpdf/qpdf/NNTree.hh
+++ b/libqpdf/qpdf/NNTree.hh
@@ -6,6 +6,7 @@
#include <iterator>
#include <list>
+#include <memory>
class NNTreeDetails
{
@@ -18,9 +19,6 @@ class NNTreeDetails
class NNTreeImpl;
class NNTreeIterator: public std::iterator<
std::bidirectional_iterator_tag,
- std::pair<QPDFObjectHandle, QPDFObjectHandle>,
- void,
- std::pair<QPDFObjectHandle, QPDFObjectHandle>*,
std::pair<QPDFObjectHandle, QPDFObjectHandle>>
{
friend class NNTreeImpl;
@@ -41,6 +39,7 @@ class NNTreeIterator: public std::iterator<
return t;
}
reference operator*();
+ pointer operator->();
bool operator==(NNTreeIterator const& other) const;
bool operator!=(NNTreeIterator const& other) const
{
@@ -63,6 +62,7 @@ class NNTreeIterator: public std::iterator<
// ABI: for qpdf 11, make qpdf a reference
NNTreeIterator(NNTreeImpl& impl);
+ void updateIValue(bool allow_invalid = true);
bool deepen(QPDFObjectHandle node, bool first, bool allow_empty);
void setItemNumber(QPDFObjectHandle const& node, int);
void addPathElement(QPDFObjectHandle const& node, int kid_number);
@@ -79,6 +79,7 @@ class NNTreeIterator: public std::iterator<
std::list<PathElement> path;
QPDFObjectHandle node;
int item_number;
+ value_type ivalue;
};
class NNTreeImpl
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-07-06 02:33:57 +0200