From 4d2aa29ee7c25b7f36cb3a18ead16c968f62494a Mon Sep 17 00:00:00 2001 From: jonathanwxh-cell Date: Mon, 9 Nov 2026 18:04:02 +0800 Subject: [PATCH] fix(preflight): resolve indirect spot families, null dict entries, and numeric equality (#6679) --- crates/preflight/src/spot.rs | 167 +++++++++++++++++++++++++++++++++-- 1 file changed, 158 insertions(+), 9 deletions(-) diff --git a/crates/preflight/src/spot.rs b/crates/preflight/src/spot.rs index 8367d8d28a..b75512fe37 100644 --- a/crates/preflight/src/spot.rs +++ b/crates/preflight/src/spot.rs @@ -64,7 +64,7 @@ impl Scan<'_> { } match o { Object::Array(a) => { - match a.first().and_then(Object::as_name) { + match a.first().map(|v| self.doc.resolve(v)).as_deref().and_then(Object::as_name) { Some(b"Separation") => self.separation(a), Some(b"DeviceN") => self.devicen(a), _ => {} @@ -138,14 +138,23 @@ impl Scan<'_> { } } - /// Whether `o` is `[/Separation name ...]` for the colorant `name`. + /// Whether `o` is `[/Separation name alternateSpace tintTransform]` for the colorant `name`, + /// with a non-null alternate space and tint transform (ISO 32000-1 8.6.6.4 and 7.3.9). fn separation_named(&self, o: &Object, name: &[u8]) -> bool { let o = self.doc.resolve(o); - let Some([kind, n, ..]) = o.as_array().map(Vec::as_slice) else { return false }; - kind.as_name() == Some(b"Separation") && self.doc.resolve(n).as_name() == Some(name) + let Some([kind, n, alt, tint, ..]) = o.as_array().map(Vec::as_slice) else { return false }; + self.doc.resolve(kind).as_name() == Some(b"Separation") + && self.doc.resolve(n).as_name() == Some(name) + && !matches!(&*self.doc.resolve(alt), Object::Null) + && !matches!(&*self.doc.resolve(tint), Object::Null) } } +/// Whether integer `i` and real `r` have the same numeric value (ISO 32000-1 7.3.3). +fn same_number(i: i64, r: f64) -> bool { + r.is_finite() && r.fract() == 0.0 && (i as f64) == r && (r as i64) == i && (i as f64 as i128) == i128::from(i) +} + /// Compares definitions, remembering which reference pairs it found equal, so a structure shared /// by many definitions is compared once, within [`MAX_COMPARE_STEPS`] and [`MAX_COMPARE_BYTES`]. struct Compare<'a> { @@ -158,13 +167,18 @@ struct Compare<'a> { } impl Compare<'_> { + /// Whether `v` is present (not `null` or a reference to no object, ISO 32000-1 7.3.7 and 7.3.9). + fn is_present(&self, v: &Object) -> bool { + !matches!(&*self.doc.resolve(v), Object::Null) + } + /// Whether `a` and `b` are the same object, wherever their parts are stored: references are /// followed (to [`MAX_COMPARE_DEPTH`]), so two identical streams under different object /// numbers are the same, and streams compare by their decoded data. Once the steps or the /// decode allowance run out, nothing more is called different. fn same(&mut self, a: &Object, b: &Object, depth: u8) -> bool { let pair = match (a, b) { - (Object::Ref(x), Object::Ref(y)) if x == y || self.equal.contains(&(*x, *y)) => return true, + (Object::Ref(x), Object::Ref(y)) if x == y || self.equal.contains(&(*x, *y)) || self.equal.contains(&(*y, *x)) => return true, (Object::Ref(x), Object::Ref(y)) => Some((*x, *y)), _ => None, }; @@ -179,6 +193,7 @@ impl Compare<'_> { (Object::Array(x), Object::Array(y)) => x.len() == y.len() && x.iter().zip(y).all(|(p, q)| self.same(p, q, deeper)), (Object::Dict(x), Object::Dict(y)) => self.same_dict(x, y, &[], deeper), (Object::Stream(x), Object::Stream(y)) => self.same_data(x, y, deeper) && self.same_dict(&x.dict, &y.dict, &ENCODING, deeper), + (Object::Int(x), Object::Real(y)) | (Object::Real(y), Object::Int(x)) => same_number(*x, *y), (x, y) => x == y, }; if same && let Some(pair) = pair { @@ -187,16 +202,24 @@ impl Compare<'_> { same } - /// Whether two dictionaries hold the same entries, those keyed in `skip` aside. + /// Whether two dictionaries hold the same non-null entries (ISO 32000-1 7.3.7), those keyed + /// in `skip` aside. fn same_dict(&mut self, a: &Dict, b: &Dict, skip: &[&[u8]], depth: u8) -> bool { - let kept = |d: &Dict| d.iter().filter(|(k, _)| !skip.contains(&k.as_slice())).count(); - kept(a) == kept(b) && a.iter().filter(|(k, _)| !skip.contains(&k.as_slice())).all(|(k, v)| b.get(k).is_some_and(|w| self.same(v, w, depth))) + let kept = |c: &Self, d: &Dict| d.iter().filter(|(k, v)| !skip.contains(&k.as_slice()) && c.is_present(v)).count(); + if kept(self, a) != kept(self, b) { + return false; + } + a.iter() + .filter(|(k, v)| !skip.contains(&k.as_slice()) && self.is_present(v)) + .collect::>() + .into_iter() + .all(|(k, v)| b.get(k).filter(|w| self.is_present(w)).is_some_and(|w| self.same(v, w, depth))) } /// Whether two streams hold the same data, however each is encoded. Data that can't be /// decoded within the allowance is not called different. fn same_data(&mut self, a: &Stream, b: &Stream, depth: u8) -> bool { - let stored_alike = |c: &mut Self, k: &[u8]| match (a.dict.get(k), b.dict.get(k)) { + let stored_alike = |c: &mut Self, k: &[u8]| match (a.dict.get(k).filter(|v| c.is_present(v)), b.dict.get(k).filter(|v| c.is_present(v))) { (None, None) => true, (Some(x), Some(y)) => c.same(x, y, depth), _ => false, @@ -210,3 +233,129 @@ impl Compare<'_> { } } } + +#[cfg(test)] +mod tests { + use std::collections::BTreeSet; + use std::sync::Arc; + + use pdfcraft_cos::{Dict, Document, Object}; + + use super::{Findings, check, same_number}; + use crate::{Level, objects, verify}; + + fn build(objs: &[&str]) -> Document { + let mut out = b"%PDF-1.7\n%\xE2\xE3\xCF\xD3\n".to_vec(); + let mut offsets = Vec::new(); + for (i, o) in objs.iter().enumerate() { + offsets.push(out.len()); + out.extend_from_slice(format!("{} 0 obj\n{o}\nendobj\n", i + 1).as_bytes()); + } + let xref = out.len(); + out.extend_from_slice(format!("xref\n0 {}\n0000000000 65535 f \n", objs.len() + 1).as_bytes()); + for o in offsets { + out.extend_from_slice(format!("{o:010} 00000 n \n").as_bytes()); + } + let id = "/ID [<00112233445566778899AABBCCDDEEFF> <00112233445566778899AABBCCDDEEFF>]"; + out.extend_from_slice(format!("trailer\n<< /Size {} /Root 1 0 R {id} >>\nstartxref\n{xref}\n%%EOF\n", objs.len() + 1).as_bytes()); + Document::open(Arc::new(out)).unwrap() + } + + fn spot_findings(spaces: &str, extra: &[&str]) -> Findings { + let page = format!("<< /Type /Page /Parent 2 0 R /Resources << /ColorSpace << {spaces} >> >> >>"); + let mut objs = vec![ + "<< /Type /Catalog /Pages 2 0 R >>", + "<< /Type /Pages /Kids [3 0 R] /Count 1 /MediaBox [0 0 200 200] >>", + &page, + "<< /FunctionType 2 /Domain [0 1] /C0 [1 1 1] /C1 [1 0 0] /N 1 >>", + "<< /FunctionType 2 /Domain [0 1] /C0 [1 1 1] /C1 [0 1 0] /N 1 >>", + "/Separation", + "/DeviceN", + ]; + objs.extend_from_slice(extra); + let doc = build(&objs); + let verified: Vec = verify(&doc, Level::A2b).into_iter().filter(|i| i.clause == "6.2.4.4").map(|i| i.message).collect(); + let found = check(&doc, &objects(&doc)); + assert_eq!(verified.len(), found.differing.len() + found.undefined.len()); + found + } + + #[test] + fn resolves_indirect_separation_and_devicen_family_names() { + // Object 6 is `/Separation` and object 7 is `/DeviceN`. + let found = spot_findings("/A [6 0 R /Gold /DeviceRGB 4 0 R] /B [/Separation /Gold /DeviceRGB 5 0 R]", &[]); + assert_eq!(found.differing, BTreeSet::from(["Gold".to_string()])); + + let found = spot_findings("/A [7 0 R [/Foil] /DeviceRGB 4 0 R << /Colorants << >> >>]", &[]); + assert_eq!(found.undefined, BTreeSet::from(["Foil".to_string()])); + + // A `/Colorants` entry whose `/Separation` family name is indirect defines the colorant. + let found = spot_findings("/A [7 0 R [/Foil] /DeviceRGB 4 0 R << /Colorants << /Foil [6 0 R /Foil /DeviceRGB 4 0 R] >> >>]", &[]); + assert_eq!(found, Findings::default()); + } + + #[test] + fn rejects_incomplete_or_null_operand_colorant_separations() { + for bad in [ + "[/Separation /Spot]", + "[/Separation /Spot /DeviceRGB]", + "[/Separation /Spot null 4 0 R]", + "[/Separation /Spot /DeviceRGB null]", + "[/Separation /Spot 99 0 R 4 0 R]", + "[/Separation /Spot /DeviceRGB 99 0 R]", + ] { + let spaces = format!("/A [/DeviceN [/Spot] /DeviceRGB 4 0 R << /Colorants << /Spot {bad} >> >>]"); + let found = spot_findings(&spaces, &[]); + assert_eq!(found.undefined, BTreeSet::from(["Spot".to_string()]), "{bad}"); + } + let valid = "/A [/DeviceN [/Spot] /DeviceRGB 4 0 R << /Colorants << /Spot [/Separation /Spot /DeviceRGB 4 0 R] >> >>]"; + assert_eq!(spot_findings(valid, &[]), Findings::default()); + } + + #[test] + fn ignores_null_dictionary_entries_and_matches_int_real_numbers() { + let extra = [ + "<< /FunctionType 2 /Domain [0.0 1.0] /C0 [1.0 1.0 1.0] /C1 [1.0 0.0 0.0] /N 1.0 /Range null /Encode 99 0 R >>", + "<< /FunctionType 4 /Domain [0 1] /Range [0 1 0 1 0 1] /Length 15 >>\nstream\n{ dup dup pop }\nendstream", + "<< /FunctionType 4 /Domain [0.0 1.0] /Range [0.0 1.0 0.0 1.0 0.0 1.0] /Filter null /DecodeParms null /Length 15 >>\nstream\n{ dup dup pop }\nendstream", + "<< /FunctionType 2 /Domain [0 1] /C0 [1 1 1] /C1 [1 0.5 0] /N 1 >>", + ]; + // Object 8 has float equivalents of object 4's integers plus null/dangling optional keys. + let found = spot_findings("/A [/Separation /Red /DeviceRGB 4 0 R] /B [/Separation /Red /DeviceRGB 8 0 R]", &extra); + assert_eq!(found, Findings::default()); + + // Object 9 and object 10 are identical Type 4 streams where object 10 has `/Filter null /DecodeParms null` and float domain/range. + let found = spot_findings("/A [/Separation /Red /DeviceRGB 9 0 R] /B [/Separation /Red /DeviceRGB 10 0 R]", &extra); + assert_eq!(found, Findings::default()); + + // Genuinely different numeric values still report differing. + let found = spot_findings("/A [/Separation /Red /DeviceRGB 8 0 R] /B [/Separation /Red /DeviceRGB 11 0 R]", &extra); + assert_eq!(found.differing, BTreeSet::from(["Red".to_string()])); + + // Precision-losing large integers do not falsely match rounded floats. + let mut doc = build(&[ + "<< /Type /Catalog /Pages 2 0 R >>", + "<< /Type /Pages /Kids [3 0 R] /Count 1 /MediaBox [0 0 200 200] >>", + "<< /Type /Page /Parent 2 0 R >>", + ]); + let mut fn_int = Dict::new(); + fn_int.set(b"N".to_vec(), Object::Int(i64::MAX)); + let mut fn_real = Dict::new(); + fn_real.set(b"N".to_vec(), Object::Real(i64::MAX as f64)); + let r_int = doc.add(Object::Dict(fn_int)); + let r_real = doc.add(Object::Dict(fn_real)); + let sep_a = Object::Array(vec![Object::name("Separation"), Object::name("Big"), Object::name("DeviceGray"), Object::Ref(r_int)]); + let sep_b = Object::Array(vec![Object::name("Separation"), Object::name("Big"), Object::name("DeviceGray"), Object::Ref(r_real)]); + doc.add(sep_a); + doc.add(sep_b); + let found = check(&doc, &objects(&doc)); + assert_eq!(found.differing, BTreeSet::from(["Big".to_string()])); + + assert!(same_number(0, -0.0)); + assert!(same_number(i64::MIN, i64::MIN as f64)); + assert!(!same_number(i64::MIN + 1, (i64::MIN + 1) as f64)); + assert!(!same_number(0, f64::NAN)); + assert!(!same_number(0, f64::INFINITY)); + assert!(!same_number(0, f64::NEG_INFINITY)); + } +}