EPDFText_GetCharGeometry crashes with null pointer on malformed PDFs #85

Calling EPDFText_GetCharGeometry on broken or fuzzed PDFs causes a segmentation fault (AddressSanitizer: SEGV).

This happens when a text object in the PDF has text but no font set.

Crash Trace

#0 CPDF_TextState::GetFont() const at cpdf_textstate.cpp:29
#1 GetCharLocalBoxes(...) at cpdf_textpage.cpp:289
#2 CPDF_TextPage::GetCharLocalGeometry(...) at cpdf_textpage.cpp:678
#3 EPDFText_GetCharGeometry(...) at fpdf_text.cpp:396

Due to this in jpdfium_redact.cpp, EPDFText_GetCharGeometry was removed from bridge. Currently, PDF passed with normal /Rect bounding boxes to EmbedPDF redaction instead of character quads. This workaround may yield some reliability issues, so if/when this fixed, evaluate to migrate back.