OpenSystemsDevelopment / qpdf

…r improved clarity and safety. Update related methods and references accordingly.

… for improved code readability and maintainability.

…isting code used 'last_object_description' and reported the error against a random unrelated object.

…ine logic, update calls across codebase, and streamline method implementation.

… `QPDFPageDocumentHelper`, consolidate redundant logic, and streamline method calls.

…e includes, and streamline page-related logic.

…gin`/`end` methods, update calls across codebase, and streamline page handling logic.

…che`, update calls, streamline initialization, and enhance assertion usage.

…` to `Pages`, update methods to use relocated fields, and streamline cache handling.

…::removePage` to use `Pages::erase`, streamline cache handling in `Pages::update_cache`.

…ges::all` method, add `Pages::size` and `empty` methods, move `getAllPagesInternal` to private section, streamline encapsulation, and enhance code organization.

… to improve code organization.

Relocate `Pages` methods to `QPDF::Doc` for improved encapsulation of page-related logic. Adjust all references and methods to use the new placement.

Streamline `setLastObjectDescription` usage by consolidating string construction at call sites. Relocate method to the private section to improve encapsulation and restrict access.

Relocate `Objects` to `QPDF::Doc` for improved encapsulation of object-related logic. Adjust all relevant methods and references to use the new placement.

…otations in page objects

- Repair invalid or missing Resources in page object trees with warnings
- Remove invalid Annots arrays with warnings
- Warn about duplicate annotations
- Update test cases and output to reflect new error handling.
- Improve robustness for annotation and resource validation.

…lize type conversions, and improve clarity across multiple modules.

…`warn`, streamline condition handling.

After xref reconstruction treat the input file as suspect and apply sanity checks to all subsequent object reads.

Remove `in_xref_reconstruction` flag and update references to use `reconstructed_xref` for simplified state management during xref processing. Adjust warnings for invalid dictionary keys in test output.

Converted multiple occurrences of `count()` to `contains()` throughout the codebase where the goal was to check key existence in containers. This improves code readability and aligns with modern C++ practices, particularly with C++20, making the intent more explicit and potentially aiding performance.

When validating the pages tree after xref recovery do not tree dictionaries
as page objects if more than 2 of the following are true:

- the dictionary is direct
- the /Type entry is missing or is not /Page
- the dictionary does not contain a valid /Parent entry
- the dictionary does not contain or inherit a valid /MediaBox
- the dictionary does not contain or inherit a /Resources dictionary

Such dictionaries are very unlikely to be page objects and trying to
process them may cause excessive run time and memory usage.

Do not copy duplicate pages during xref recovery.

In QPDF::getAllPagesInternal include the /Kids array in the visited set
for loop detection.

Fixes oss-fuzz issue 411312393

Except for virtual functions to avoid the need for users to update code.

This improves indentation of long strings. This commit also fixes some
trailing whitespace in ChangeLog.

Provide correct obj_gen.

This reverts commit ff2a78f579ebdd06b417e34260a17dba06e71137, reversing
changes made to 8f54319f7a6514110f4b05cbbf1cb1c9fc8cb6a0.

Ensure QPDF m->all_pages and invalid_page_found are reset if
getAllPagesInternal throws an exception.

Fixes fuzz case 71624.

Try a  limit of 50MB. For very large limits processing time before
damage is encountered may exceed oss-fuzz limits.
Add further test cases.

Reject non-dictionary Page and Pages objects.

Also add additional qpdf_fuzzer test cases.

Using search and replace.