pdftract/notes/bf-ttbb5.md
jedarden 6c668c7e42 docs(bf-ttbb5): document no-mapping.pdf generation verification
Successfully executed generate_unicode_recovery_fixtures_bin to create
no-mapping.pdf fixture (650 bytes). Validated PDF structure includes
custom /CustomNoMap font with /Differences encoding, non-AGL glyph
names, and no ToUnicode entry. Ground truth contains U+FFFD × 3.

Closes bf-ttbb5.
2026-07-03 16:13:27 -04:00

2.9 KiB
Raw Blame History

bf-ttbb5: Verification of no-mapping.pdf Generation

Date: 2026-07-03 Parent Bead: bf-1m30m Task: Verify and run no-mapping.pdf generation scripts

Execution Summary

Successfully executed the Rust generation binary generate_unicode_recovery_fixtures_bin in the encoding fixtures directory.

Command Executed

cd tests/fixtures/encoding && ./generate_unicode_recovery_fixtures_bin

Output

Generating Unicode recovery test fixtures...
  Generating no-mapping.pdf...
    -> no-mapping.pdf (expect: <U+FFFD><U+FFFD><U+FFFD>)
  Generating agl-only.pdf...
    -> agl-only.pdf (expect: Hello\nWorld)
  Generating fingerprint-match.pdf...
    -> fingerprint-match.pdf (expect: Test)
  Generating shape-match.pdf...
    -> shape-match.pdf (expect: S)

✓ All fixtures generated successfully!

Verification Results

File Creation

  • no-mapping.pdf: 650 bytes ✓
  • no-mapping.txt: 9 bytes (pre-existing ground truth) ✓

PDF Structure Validation

  • Header: Valid %PDF-1.4 ✓
  • Font: /CustomNoMap (Type1, not standard 14) ✓
  • Encoding: Custom /Differences [0 /g001 /g002 /g003]
  • Glyph Names: Non-AGL names /g001, /g002, /g003
  • ToUnicode: Absent (as required for ENCODING_NO_MAPPING test) ✓
  • Trailer: Valid with %%EOF marker ✓

Ground Truth Validation

  • Content: Three U+FFFD replacement characters (0xEF 0xBF 0xBD × 3) ✓
  • Expected: <U+FFFD><U+FFFD><U+FFFD> (as documented in bf-f0xqd-research.md) ✓

Technical Details

The generated fixture correctly implements the ENCODING_NO_MAPPING failure mode:

  • Level 1 recovery fails: No standard encoding (WinAnsi/MacRoman/Standard)
  • Level 2 recovery fails: Glyph names not in Adobe Glyph List (AGL)
  • Level 3 recovery fails: No embedded font program for fingerprinting
  • Level 4 recovery: Expected to emit U+FFFD × 3 with GLYPH_UNMAPPED diagnostic

Artifacts Produced

  • tests/fixtures/encoding/no-mapping.pdf - Main fixture
  • tests/fixtures/encoding/no-mapping.txt - Ground truth (pre-existing)
  • tests/fixtures/encoding/agl-only.pdf - Generated alongside
  • tests/fixtures/encoding/fingerprint-match.pdf - Generated alongside
  • tests/fixtures/encoding/shape-match.pdf - Generated alongside

References

  • Research document: notes/bf-f0xqd-research.md (sections 4.4, 9)
  • Generation script: tests/fixtures/encoding/generate_unicode_recovery_fixtures.rs
  • Binary: tests/fixtures/encoding/generate_unicode_recovery_fixtures_bin

Conclusion

Status: COMPLETE ✓

The generation script executed without errors and produced a valid no-mapping.pdf fixture that meets all acceptance criteria:

  • ✓ Script executed successfully
  • ✓ No errors during execution
  • ✓ no-mapping.pdf created in encoding fixtures directory
  • ✓ PDF structure validated (custom encoding, non-AGL glyphs, no ToUnicode)
  • ✓ Ground truth file contains expected U+FFFD × 3