LadybirdBrowser/ladybird
1
1
Fork 0
mirror of https://github.com/LadybirdBrowser/ladybird.git synced 2024-09-20 09:49:15 +03:00
Code Issues Packages Projects Releases Wiki Activity

LibPDF: Use a RAII object to restore state in recursive render

Browse Source 
Previously, if one operator returned an error, the TRY() would cause
us to return without restoring the outer graphics state, leading to
problems such as handing a 3-tuple to a grayscale color space
(because the inner object set up a grayscale color space that we
failed to dispose of).

Makes us crash later on page 43 of
https://devstreaming-cdn.apple.com/videos/wwdc/2017/821kjtggolzxsv/821/821_get_started_with_display_p3.pdf
This commit is contained in:
Nico Weber 2023-10-18 11:46:11 -04:00 committed by Tim Flynn
parent c58193bafa
commit b835d2bd66
Notes: sideshowbarker 2024-07-16 21:45:42 +09:00 
Author: https://github.com/nico
Commit: https://github.com/SerenityOS/serenity/commit/b835d2bd66
Pull-request: https://github.com/SerenityOS/serenity/pull/21489
1 changed files with 19 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

21
Userland/Libraries/LibPDF/Renderer.cpp
View File

@ -644,7 +644,25 @@ RENDERER_HANDLER(paint_xobject)
return {};
}
MUST(handle_save_state({}));
// Use a RAII object to restore the graphics state, to make sure it gets restored even if
// a TRY(handle_operator()) causes us to exit the operators loop early.
class ScopedState {
public:
ScopedState(Renderer& renderer)
: m_renderer(renderer)
{
MUST(m_renderer.handle_save_state({}));
}
~ScopedState()
{
MUST(m_renderer.handle_restore_state({}));
}
private:
Renderer& m_renderer;
};
ScopedState scoped_state { *this };
Vector<Value> matrix;
if (xobject->dict()->contains(CommonNames::Matrix)) {
matrix = xobject->dict()->get_array(m_document, CommonNames::Matrix).value()->elements();
@ -655,7 +673,6 @@ RENDERER_HANDLER(paint_xobject)
auto operators = TRY(Parser::parse_operators(m_document, xobject->bytes()));
for (auto& op : operators)
TRY(handle_operator(op, xobject_resources));
MUST(handle_restore_state({}));
return {};
}