From: Ben Pfaff <blp@cs.stanford.edu>
Date: Tue, 14 Oct 2025 23:36:11 +0000 (-0700)
Subject: fix
X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=09a6c41b27a139a2f67035ee9c4e99aa2dc4697f;p=pspp

fix
---

diff --git a/rust/doc/src/spv/light-detail.md b/rust/doc/src/spv/light-detail.md
index f89eb5d659..b42b6ebbe6 100644
--- a/rust/doc/src/spv/light-detail.md
+++ b/rust/doc/src/spv/light-detail.md
@@ -661,7 +661,7 @@ X3 =>
     double[small] 01
     (string[dataset] string[datafile] i0 int32[date] i0)?
     Y2
-    (int32[x22] i0 01?)?
+    (int32[x22] i0 bool[x25]?)?
 ```
 
 `small` is a small real number.  In the corpus, it overwhelmingly
@@ -686,8 +686,10 @@ a null byte (a valid string never will).
 
 `x22` is usually 0 or 2000000.
 
-A writer may safely use 4 for `x21` and omit `x22` and the other
-optional bytes at the end.
+`x25` is usually `01`.
+
+A writer may safely use 4 for `x21` and omit `x22`, `x25`, and the
+other optional bytes at the end.
 
 ### Encoding
 
diff --git a/rust/pspp/src/output/spv/light.rs b/rust/pspp/src/output/spv/light.rs
index 22a01e8386..fdc2864aa5 100644
--- a/rust/pspp/src/output/spv/light.rs
+++ b/rust/pspp/src/output/spv/light.rs
@@ -712,13 +712,13 @@ where
         endian: binrw::Endian,
         args: Self::Args<'_>,
     ) -> BinResult<Self> {
-        let start = reader.stream_position()?;
         let count = u32::read_options(reader, endian, ())? as u64;
+        let start = reader.stream_position()?;
         let end = start + count;
         let mut inner = reader.take_seek(count);
         let result = <T>::read_options(&mut inner, Endian::Little, args)?;
         let pos = inner.stream_position()?;
-        if pos < end {
+        if pos != end {
             let consumed = pos - start;
             return Err(binrw::Error::Custom {
                 pos,
@@ -1001,8 +1001,8 @@ struct X3Tail {
     _x22: i32,
     #[br(temp, assert(_zero == 0))]
     _zero: i32,
-    #[br(temp)]
-    _one: Optional<One>,
+    #[br(temp, assert(_x25.is_none_or(|x25| x25 == 0 || x25 == 1)))]
+    _x25: Optional<u8>,
 }
 
 #[binread]