M2: the operand-cap patch is hayro-syntax patch 28 (#4260)

Main took hayro-syntax patches 26 and 27 (xref streams), so the patch
that keeps up to 256 operands per instruction moves to 28 in
vendor/README.md and in every comment that cites it.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0175FWj4xFhMhSH3UpMU8DSC

crates/render/src/raster.rs

@@ -8170,7 +8170,7 @@ trailer << /Root 1 0 R >>
     mod default_colour_spaces;
 
     // #4260: DeviceN colours with many inks, and tint transforms that cannot be evaluated
-    // (vendored hayro-syntax patch 26, hayro-interpret patch 55).
+    // (vendored hayro-syntax patch 28, hayro-interpret patch 55).
     mod devicen_inks;
 
     /// #3109 / #3116: clipping-only text (`7 Tr`) installs a clip for subsequent painting

crates/render/src/raster/tests/devicen_inks.rs

@@ -1,7 +1,7 @@
 //! #4260: a DeviceN colour with more inks than the content parser held operands for, and a
 //! colour whose tint transform cannot be evaluated (ISO 32000-2 §8.6.6.5).
 //!
-//! The content parser kept at most ten operands per operator (vendored hayro-syntax patch 26):
+//! The content parser kept at most ten operands per operator (vendored hayro-syntax patch 28):
 //! the eleventh operand of a twelve-ink `scn` ended the whole content stream, so the page came
 //! out blank with no error. A tint transform that cannot be evaluated painted the alternate
 //! space's initial colour without a word (vendored hayro-interpret patch 55): it now says so.

vendor/hayro-syntax/src/content/mod.rs

@@ -50,10 +50,10 @@ use smallvec::SmallVec;
 // 6 operands are used for example for ctm or cubic curves,
 // but anything above should be pretty rare (only for example for
 // DeviceN color spaces, or invalid PDF files). So we settle on 10.
-// PdfCraft patch (26): this is now only how many operands are held inline; see `MAX_OPERANDS`.
+// PdfCraft patch (28): this is now only how many operands are held inline; see `MAX_OPERANDS`.
 const OPERANDS_THRESHOLD: usize = 10;
 
-/// PdfCraft patch (26): the most operands one instruction keeps. The stack held ten, and the
+/// PdfCraft patch (28): the most operands one instruction keeps. The stack held ten, and the
 /// eleventh operand of an instruction ended the whole content stream, so a DeviceN colour of
 /// eleven or more inks (ISO 32000-2 §8.6.6.5 allows "an arbitrary number of colour
 /// components") blanked the rest of the page (#4260). An `SCN`/`scn` for the largest DeviceN
@@ -445,7 +445,7 @@ impl<'a> UntypedIter<'a> {
 
                 self.operator = Some(operator);
                 self.committed = self.reader.offset();
-                // PdfCraft patch (26): operands in reading order, if some were dropped.
+                // PdfCraft patch (28): operands in reading order, if some were dropped.
                 self.stack.settle();
                 return Some(Instruction {
                     operands: &self.stack,
@@ -605,12 +605,12 @@ impl<'b, 'a> Instruction<'b, 'a> {
 pub struct Stack<'a> {
     // TODO: Explore using an object pool to avoid repeatedly
     // allocating/deallocating objects.
-    // PdfCraft patch (26): up to `MAX_OPERANDS` operands, the first `OPERANDS_THRESHOLD` inline.
+    // PdfCraft patch (28): up to `MAX_OPERANDS` operands, the first `OPERANDS_THRESHOLD` inline.
     data: SmallVec<[Object<'a>; OPERANDS_THRESHOLD]>,
-    /// PdfCraft patch (26): once `data` is full, the slot of its oldest operand, which the next
+    /// PdfCraft patch (28): once `data` is full, the slot of its oldest operand, which the next
     /// operand replaces. Always 0 while the stack is not full, and after `settle`.
     oldest: usize,
-    /// PdfCraft patch (26): whether operands were dropped since the stack was last settled.
+    /// PdfCraft patch (28): whether operands were dropped since the stack was last settled.
     dropped: bool,
 }
 
@@ -630,7 +630,7 @@ impl<'a> Stack<'a> {
         }
     }
 
-    /// PdfCraft patch (26): push an operand, dropping the oldest once `MAX_OPERANDS` are held
+    /// PdfCraft patch (28): push an operand, dropping the oldest once `MAX_OPERANDS` are held
     /// (see `MAX_OPERANDS`). Never fails: it used to, and the failure ended the content stream.
     fn push(&mut self, operand: Object<'a>) -> Option<()> {
         if self.data.len() < MAX_OPERANDS {
@@ -646,7 +646,7 @@ impl<'a> Stack<'a> {
         Some(())
     }
 
-    /// PdfCraft patch (26): put the operands back in the order they were read, oldest first,
+    /// PdfCraft patch (28): put the operands back in the order they were read, oldest first,
     /// after `push` dropped some. Called before the instruction is handed out.
     fn settle(&mut self) {
         if self.dropped {
@@ -703,7 +703,7 @@ impl Debug for Stack<'_> {
 
 impl Clone for Stack<'_> {
     fn clone(&self) -> Self {
-        // PdfCraft patch (26): a plain copy (pushing each operand again could no longer fail).
+        // PdfCraft patch (28): a plain copy (pushing each operand again could no longer fail).
         Self {
             data: self.data.clone(),
             oldest: self.oldest,

vendor/hayro-syntax/src/content/ops.rs

@@ -152,7 +152,7 @@ f
         assert!(iter.next().is_none());
     }
 
-    /// PdfCraft patch (26): a twelve-ink DeviceN colour's `scn` keeps all twelve operands, and
+    /// PdfCraft patch (28): a twelve-ink DeviceN colour's `scn` keeps all twelve operands, and
     /// the instructions after it are still read (#4260). The eleventh operand ended the stream.
     #[test]
     fn scn_with_twelve_components_keeps_them_all() {
@@ -171,7 +171,7 @@ f
         assert!(iter.next().is_none());
     }
 
-    /// PdfCraft patch (26): past the operand cap the oldest operands are dropped, in order, and
+    /// PdfCraft patch (28): past the operand cap the oldest operands are dropped, in order, and
     /// the operator reads the ones nearest to it.
     #[test]
     fn operands_past_the_cap_keep_the_latest_in_order() {