Merge upstream develop into QC develop (2026-11-11)

Cargo.toml

@@ -214,7 +214,7 @@ parquet = "59.2"
 parquet-variant = "59.2"
 parquet-variant-compute = "59.2"
 paste = "1.0.15"
-pco = "1.0.1"
+pco = "1.1.0"
 percent-encoding = "2.3.2"
 pin-project-lite = "0.2.15"
 primitive-types = { version = "0.14.0" }

encodings/pco/src/array/mod.rs

@@ -604,9 +604,6 @@ impl PcoData {
                     let old_len = decompressed_values.len();
                     let new_len = old_len + page_n_values;
                     decompressed_values.reserve(page_n_values);
-                    unsafe {
-                        decompressed_values.set_len(new_len);
-                    }
                     let page: &[u8] = self
                         .pages
                         .get(page_idx)
@@ -626,8 +623,15 @@ impl PcoData {
                     let mut pd = cd
                         .page_decompressor(page, page_n_values)
                         .map_err(vortex_err_from_pco)?;
-                    pd.read(&mut decompressed_values[old_len..new_len])
+                    let progress = pd
+                        .read_uninit(&mut decompressed_values.spare_capacity_mut()[..page_n_values])
                         .map_err(vortex_err_from_pco)?;
+                    vortex_ensure_eq!(progress.n_processed, page_n_values);
+                    // SAFETY: `read_uninit` initialized all `page_n_values` spare elements,
+                    // as confirmed by the processed count above.
+                    unsafe {
+                        decompressed_values.set_len(new_len);
+                    }
 
                     chunk_decompressor = Some(cd);
                 } else {

encodings/pco/src/probe.rs

@@ -21,6 +21,7 @@ use vortex_array::validity::Validity;
 use vortex_buffer::BufferMut;
 use vortex_error::VortexExpect;
 use vortex_error::VortexResult;
+use vortex_error::vortex_ensure_eq;
 use vortex_mask::Mask;
 
 use crate::Pco;
@@ -156,10 +157,13 @@ fn decode_page<T: Number + NativePType>(
         .page_decompressor(buffer, n_values)
         .map_err(vortex_err_from_pco)?;
     let mut values = BufferMut::<T>::with_capacity_in(n_values, ctx.allocator().clone());
-    // SAFETY: the buffer reserves `n_values` elements, and the page decompressor was built for
-    // exactly that count, so `read` writes every element before anything observes it.
+    let progress = decoder
+        .read_uninit(&mut values.spare_capacity_mut()[..n_values])
+        .map_err(vortex_err_from_pco)?;
+    vortex_ensure_eq!(progress.n_processed, n_values);
+    // SAFETY: `read_uninit` initialized all `n_values` spare elements, as confirmed by the
+    // processed count above.
     unsafe { values.set_len(n_values) };
-    decoder.read(&mut values).map_err(vortex_err_from_pco)?;
     Ok(PrimitiveArray::new(values.freeze(), Validity::NonNullable))
 }