libcupsfilters 2.2.0 - First actual feature release after 2.0.0 three years ago

First actual feature release after libcupsfilters 2.0.0 three years ago: Done away with C++ using PDFio instead of QPDF and Poppler's pdftoppm instead of libpoppler, non-Latin plain text support, JPEG XL input support, print quality enhancement with Ghostscript, full-fledged CI testing for x86_64, ARM 32 and 64, RISC-V, and CUPS 2.x, 2.5.x, 3.x, bugs from security audit fixed, 4 CVEs fixed, and more ...

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• Eliminated the use of C++ in libcupsfilters, to get all regular C
  • Replaced QPDF by PDFio as PDF manipulation library in libcupsfilters Modified the filter functions cfFilterPDFToPDF(), cfFilterPCLmToRaster(), cfFilterPWGToPDF(), cfFilterBannerToPDF(). Also turned the code from C++ into C.
  • In cfFilterPDFToRaster() replaced use of libpoppler by using PDFio and also the external executable pdftoppm of poppler-utils, also here turned C++ code into C
  • Made sure that the API/ABI of libcupsfilters did not change
  • Also added extra CI tests via cupsfilters/test-filter-cases.txt
  • PDFio 1.6.4 now required for building libcupsfilters Older versions have bugs.
  • GSoC 2024 project of Uddhav Phatak: Final report
  • Thanks, Uddhav, for your excellent work!
  • Pull requests #71, #101, #103, #105, #115, #124, #146, #154, #171
• Non-Latin language input support for cfFilterTextToPDF()
  • Removed FC_MONO constraint to allow proportional fonts Some languages have non-monospaced scripts and now they can correctly load their intended fonts.
  • Default to UTF-8 when charset metadata is missing cfFilterTextToPDF() expects UTF-8 input by default now
  • Add Devanagari Unicode range to utf-8 charsets
  • Thanks to Shreyansh Tiwari
  • Pull requests #120, #140, #141
• Added JPEG‑XL Support to libcupsfilters Now jobs in the high-quality JPEG-XL image format can be sent directly to CUPS and cfFilterImageTo...() filter functions read and convert these files. Winter of Code 4.0 project by Titiksha Bansal. Thanks a lot. (Pull request #82)
• Print quality improvements
  • In cfFilterGhostscript() introduced cupsHalftoneType dithering algorithms Controlled with halftone-type job option or cupsHalftoneType PPD option. Added stochastic halftoning, bi-level threshold, an algorithm from foo2zjs, 8x8, genordered, and spot from PDF (Pull request #92, #160)
  • Added user-settable gamma parameter and removed Ghostscript's default one
  • Fixed 1-bit mono dithering of 100% black pixel.
    Prevents white holes in the text
  • Thanks to ValdikSS
• CI: Implemented complete GitHub Actions pipeline (Build, Unit tests, CodeQL, Cppcheck)
  • GitHub workflow for CI added
  • Static analysis (CodeQL, Cppcheck)
  • Build and unit tests multiple architecture (x86 64-bit, ARM 64- and 32-bit, and RISC-V 64-bit) and for different CUPS versions (2.4.x, 2.5.x, 3.x). Tests on 12 combos
  • Emulations used for ARM 32-bit and RISC-V
  • Use make check and also Debian's autopkgtests as unit tests
  • Workflows optimized with caching and parallel jobs
  • Fixed several issues discovered with the added static analysis
  • Part of Rohit Kumar's GSoC 2026 project. Thanks a lot.
  • Pull requests #132, #133, #134, #135, #137, #157, #158, #159
• CI: Improvements of unit tests
  • Add malformed PDF testcase for pdftopdf validation (Pull request #131)
  • Added UTF-8 non-Latin regression coverage for Cyrillic, Greek, Arabic (Pull request #129)
  • Let testfilters just go through all lines of test cases instead of using line count as a parameter (Pull request #128)
  • Add optional manual FilterChain() support to testfilters Manually providing a filter chain is optional, if not supplied, it is set automatically as before (Pull request #122)
  • Added a deterministic build-time multi-page UTF-8 Lorem-Ipsum generator (Pull request #119)
  • Thanks to Shreyansh Tiwari
• Fixed (crasher) bugs found in security audit by 7ASecurity
  • Crash from wrong tag *-supported/*-default attributes in the cfIPPAttrEnumValForPrinter() function Check IPP tags (data types) to avoid NULL dereferences (OCU-01-001, Issue #149, pull request #162)
  • Crash from wrong-tag driverless IPP attributes cfGetBackSideOrientation() and cfGetPrintRenderIntent() look up several IPP attributes. Also here check tags/data types to avoid NULL dereferences (OCU-01-003, Issue #163, pull request #164)
  • Thanks to Aayush Kumar for the GitHub issue reports and the fixes
  • And thanks to 7ASecurity for the audit and to the Sovereign Tech Agency for funding the Audit
• SECURITY: Out-of-bounds write in cfFilterPDFToRaster() if PDF has too large page dimensions Crop dimensions to maximum allowed by standard, 14400x14400pt, 200x200in, 5x5m, if needed. (CVE-2025-64503)
• SECURITY: Vulnerabilities by image input with wrong color space/depth/bits-per-pixel combo
  • Fix heap-buffer overflow write in cfImageLut
  • Reject color images with 1 bit per sample
  • Reject images where the number of samples does not correspond with the color space
  • Reject images with planar color configuration
  • Reject images with vertical scanlines (CVE-2025-57812)
• SECURITY: cfFilterImageTo...(): Added error handling for libpng and libjpeg function calls to avoid the process being aborted. (Pull request #168, #169) (CVE-2026-64612)
• SECURITY: Fix possible infinite loop when parsing device IDs, also avoid empty device IDs (Pull request #170)
  (CVE-2026-64611)
• Fixed heap buffer overflow in bilinear zoom of images (Issue #142, pull request #143)
• Out-of-bounds read in NormalizeMakeModel when manufacturer name too long (Issue #136, pull request #139)
• Use ColorModel or output-mode if there's no print-color-mode (Issue #126, pull request #127)
• Fix cache thrashing for large images when cropping them (Pull request #106)
• Fix for potential heap-buffer-overflow when reading TIFF images with more than one sample per pixel (Issue #107, pull request #108)
• Unified return value of TIFF related functions to -1
• When zooming images check whether X and Y size dimensions are not zero (Pull request #86)
• pdftoraster, gsto..., mupdftopwg: Fix NULL-pointer dereference when parsing %%PDFTOPDF... comments (Pull request #94)
• pdftoraster: Check result of render_page() as it may return NULL if the page is not properly constructed (Pull request #95)
• imagetopdf: convert custom media size min_width and min_height to points (Issue #87, pull request #93)
• cfFilterChain(): Initialize return value to 0
  In some cases the function exits with non-zero status when all filters exit with no errors (zero status).
• Fixed Deadlock in filter chain when one filter fails (Issue #32, pull request #85)
• cfFilterTextToPDF(): Let all Arabic characters be rendered right-to-left (Issue #84)
• Fix build with libcups3
  • Add changed function cupsParseOptions()
  • Only define struct cups_media_s if running a version older then CUPS 2.5.x
  • Update testfilters.c to use CUPS 3.0 API with compatibility shim for CUPS 2.x and older. Given that this is an end-user program, we don't want to include libcups2-private.h. Also tweaked Makefile to link against proper CUPS library.
  • Removed unused reference to cups/backend.h
  • Pull request #153
• Allow building without fontconfig Controllable by ./configure option. When building without fontconfig, cfFilterTextToPDF() gets no-op (to keep API) (Pull request #83)
• Build-time option for alternative CJK font name ./configure option -with-cjk-fonts sets alternative name (Pull request #96)
• Fix missing sys/stat.h include for Solaris (Issue #97, pull request #130)
• Use /bin/sh for testfilters.sh to avoid dependency on bash (Pull request #67)
• cfFilterImageToPDF(): Added extra debug log messages concerning page orientation (Pull request #102)