feat(pdf): add license-safe source-edit fixture corpus (#32)

fixtures/source-edit/README.md

@@ -0,0 +1,16 @@
+# Source-edit fixture corpus
+
+Synthetic PDFs for spike #11 / issue #32. Licensed like OffPDF (MIT). No
+third-party, customer, or photographed documents. Rasters are 2×2 (or
+smaller) DeviceRGB/Gray; CID files use a tiny synthetic Type0, not a copy
+of Noto.
+
+These files describe **existing page structures**. They are **not** claimed
+editable. `manifest.json` `intent` is only `try-edit` (later attempt) or
+`unsupported-stand-in` (explicit negative). Do not add an `editable` key.
+
+Regenerate: `write_corpus_fixture(id, dest)` in
+`src-tauri/src/pdf_engine/source_edit_fixtures.rs` is the source of truth.
+After lopdf `save` it runs `qpdf in out` when qpdf is available so
+`qpdf --check` passes. Committed `*.pdf` files must be that writer’s output
+so uncompressed stream dumps match.

fixtures/source-edit/manifest.json

@@ -0,0 +1,168 @@
+{
+  "version": 1,
+  "license": "synthetic; OffPDF MIT; no third-party PDFs",
+  "fixtures": [
+    {
+      "id": "text-tj",
+      "path": "text-tj.pdf",
+      "structures": ["Tj", "rotate-0"],
+      "intent": "try-edit",
+      "failureMode": "baseline show-string",
+      "qpdf": "must-pass",
+      "geometry": { "rotate": 0, "userUnit": 1.0, "cropOffset": false }
+    },
+    {
+      "id": "text-tj-kerned",
+      "path": "text-tj-kerned.pdf",
+      "structures": ["TJ"],
+      "intent": "try-edit",
+      "failureMode": "kerning array with numeric offset",
+      "qpdf": "must-pass",
+      "geometry": { "rotate": 0, "userUnit": 1.0, "cropOffset": false }
+    },
+    {
+      "id": "text-cid-tounicode",
+      "path": "text-cid-tounicode.pdf",
+      "structures": ["CID+ToUnicode"],
+      "intent": "try-edit",
+      "failureMode": "Type0/CID with usable ToUnicode CMap",
+      "qpdf": "must-pass",
+      "geometry": { "rotate": 0, "userUnit": 1.0, "cropOffset": false }
+    },
+    {
+      "id": "text-cid-no-tounicode",
+      "path": "text-cid-no-tounicode.pdf",
+      "structures": ["CID-no-ToUnicode"],
+      "intent": "unsupported-stand-in",
+      "failureMode": "Type0/CID without usable ToUnicode CMap",
+      "qpdf": "must-pass",
+      "geometry": { "rotate": 0, "userUnit": 1.0, "cropOffset": false }
+    },
+    {
+      "id": "text-type3",
+      "path": "text-type3.pdf",
+      "structures": ["Type3"],
+      "intent": "unsupported-stand-in",
+      "failureMode": "Type 3 CharProcs",
+      "qpdf": "must-pass",
+      "geometry": { "rotate": 0, "userUnit": 1.0, "cropOffset": false }
+    },
+    {
+      "id": "text-nested-form",
+      "path": "text-nested-form.pdf",
+      "structures": ["nested-form"],
+      "intent": "unsupported-stand-in",
+      "failureMode": "text inside nested Form XObject",
+      "qpdf": "must-pass",
+      "geometry": { "rotate": 0, "userUnit": 1.0, "cropOffset": false }
+    },
+    {
+      "id": "text-rotated",
+      "path": "text-rotated.pdf",
+      "structures": ["text-rotated"],
+      "intent": "unsupported-stand-in",
+      "failureMode": "rotated text matrix",
+      "qpdf": "must-pass",
+      "geometry": { "rotate": 0, "userUnit": 1.0, "cropOffset": false }
+    },
+    {
+      "id": "text-skewed",
+      "path": "text-skewed.pdf",
+      "structures": ["text-skewed"],
+      "intent": "unsupported-stand-in",
+      "failureMode": "skewed text matrix",
+      "qpdf": "must-pass",
+      "geometry": { "rotate": 0, "userUnit": 1.0, "cropOffset": false }
+    },
+    {
+      "id": "image-unique",
+      "path": "image-unique.pdf",
+      "structures": ["image-unique"],
+      "intent": "try-edit",
+      "failureMode": "unique Image XObject on one page",
+      "qpdf": "must-pass",
+      "geometry": { "rotate": 0, "userUnit": 1.0, "cropOffset": false }
+    },
+    {
+      "id": "image-reused",
+      "path": "image-reused.pdf",
+      "structures": ["image-reused"],
+      "intent": "unsupported-stand-in",
+      "failureMode": "same Image XObject on two pages",
+      "qpdf": "must-pass",
+      "geometry": { "rotate": 0, "userUnit": 1.0, "cropOffset": false }
+    },
+    {
+      "id": "image-in-form",
+      "path": "image-in-form.pdf",
+      "structures": ["image-in-form"],
+      "intent": "unsupported-stand-in",
+      "failureMode": "Image painted from a Form",
+      "qpdf": "must-pass",
+      "geometry": { "rotate": 0, "userUnit": 1.0, "cropOffset": false }
+    },
+    {
+      "id": "image-inline",
+      "path": "image-inline.pdf",
+      "structures": ["image-inline"],
+      "intent": "unsupported-stand-in",
+      "failureMode": "inline image BI/EI",
+      "qpdf": "must-pass",
+      "geometry": { "rotate": 0, "userUnit": 1.0, "cropOffset": false }
+    },
+    {
+      "id": "image-mask",
+      "path": "image-mask.pdf",
+      "structures": ["image-mask"],
+      "intent": "unsupported-stand-in",
+      "failureMode": "Image with SMask",
+      "qpdf": "must-pass",
+      "geometry": { "rotate": 0, "userUnit": 1.0, "cropOffset": false }
+    },
+    {
+      "id": "geom-crop-offset",
+      "path": "geom-crop-offset.pdf",
+      "structures": ["crop-offset"],
+      "intent": "unsupported-stand-in",
+      "failureMode": "CropBox origin offset from MediaBox",
+      "qpdf": "must-pass",
+      "geometry": { "rotate": 0, "userUnit": 1.0, "cropOffset": true }
+    },
+    {
+      "id": "geom-user-unit",
+      "path": "geom-user-unit.pdf",
+      "structures": ["user-unit"],
+      "intent": "unsupported-stand-in",
+      "failureMode": "UserUnit not 1",
+      "qpdf": "must-pass",
+      "geometry": { "rotate": 0, "userUnit": 2.0, "cropOffset": false }
+    },
+    {
+      "id": "geom-rotate-90",
+      "path": "geom-rotate-90.pdf",
+      "structures": ["rotate-90"],
+      "intent": "unsupported-stand-in",
+      "failureMode": "page Rotate 90",
+      "qpdf": "must-pass",
+      "geometry": { "rotate": 90, "userUnit": 1.0, "cropOffset": false }
+    },
+    {
+      "id": "geom-rotate-180",
+      "path": "geom-rotate-180.pdf",
+      "structures": ["rotate-180"],
+      "intent": "unsupported-stand-in",
+      "failureMode": "page Rotate 180",
+      "qpdf": "must-pass",
+      "geometry": { "rotate": 180, "userUnit": 1.0, "cropOffset": false }
+    },
+    {
+      "id": "geom-rotate-270",
+      "path": "geom-rotate-270.pdf",
+      "structures": ["rotate-270"],
+      "intent": "unsupported-stand-in",
+      "failureMode": "page Rotate 270",
+      "qpdf": "must-pass",
+      "geometry": { "rotate": 270, "userUnit": 1.0, "cropOffset": false }
+    }
+  ]
+}

src-tauri/src/pdf_engine/mod.rs

@@ -12,6 +12,8 @@ pub mod edit_image;
 pub mod edit_overlay;
 #[cfg(test)]
 mod edit_overlay_integ;
+#[cfg(test)]
+mod source_edit_fixtures;
 pub mod metadata;
 pub mod nup;
 pub mod ocr;