Adjust the placement of the zero size check for some texture copies

wgpu-core/src/command/clear.rs

@@ -189,6 +189,8 @@ pub(super) fn clear_buffer(
         });
     }
 
+    // This must happen after parameter validation (so that errors are reported
+    // as required by the spec), but before any side effects.
     if offset == end_offset {
         log::trace!("Ignoring fill_buffer of size 0");
         return Ok(());

wgpu-core/src/command/transfer.rs

@@ -1037,6 +1037,8 @@ pub(super) fn copy_buffer_to_buffer(
         .into());
     }
 
+    // This must happen after parameter validation (so that errors are reported
+    // as required by the spec), but before any side effects.
     if size == 0 {
         log::trace!("Ignoring copy_buffer_to_buffer of size 0");
         return Ok(());
@@ -1255,6 +1257,8 @@ pub(super) fn copy_texture_to_buffer(
         .check_usage(BufferUsages::COPY_DST)
         .map_err(TransferError::MissingBufferUsage)?;
 
+    // This must happen after parameter validation (so that errors are reported
+    // as required by the spec), but before any side effects.
     if copy_size.width == 0 || copy_size.height == 0 || copy_size.depth_or_array_layers == 0 {
         log::trace!("Ignoring copy_texture_to_buffer of size 0");
         return Ok(());
@@ -1376,12 +1380,6 @@ pub(super) fn copy_texture_to_texture(
         .into());
     }
 
-    // Handle texture init *before* dealing with barrier transitions so we
-    // have an easier time inserting "immediate-inits" that may be required
-    // by prior discards in rare cases.
-    handle_src_texture_init(state, source, copy_size, src_texture)?;
-    handle_dst_texture_init(state, destination, copy_size, dst_texture)?;
-
     let src_raw = src_texture.try_raw(state.snatch_guard)?;
     src_texture
         .check_usage(TextureUsages::COPY_SRC)
@@ -1391,11 +1389,19 @@ pub(super) fn copy_texture_to_texture(
         .check_usage(TextureUsages::COPY_DST)
         .map_err(TransferError::MissingTextureUsage)?;
 
+    // This must happen after parameter validation (so that errors are reported
+    // as required by the spec), but before any side effects.
     if copy_size.width == 0 || copy_size.height == 0 || copy_size.depth_or_array_layers == 0 {
         log::trace!("Ignoring copy_texture_to_texture of size 0");
         return Ok(());
     }
 
+    // Handle texture init *before* dealing with barrier transitions so we
+    // have an easier time inserting "immediate-inits" that may be required
+    // by prior discards in rare cases.
+    handle_src_texture_init(state, source, copy_size, src_texture)?;
+    handle_dst_texture_init(state, destination, copy_size, dst_texture)?;
+
     let src_pending =
         state
             .tracker

wgpu-core/src/device/queue.rs

@@ -537,6 +537,8 @@ impl Queue {
         let data_size = if let Some(data_size) = wgt::BufferSize::new(data_size) {
             data_size
         } else {
+            // This must happen after parameter validation (so that errors are reported
+            // as required by the spec), but before any side effects.
             log::trace!("Ignoring write_buffer of size 0");
             return Ok(());
         };
@@ -791,6 +793,8 @@ impl Queue {
 
         let dst_raw = dst.try_raw(&snatch_guard)?;
 
+        // This must happen after parameter validation (so that errors are reported
+        // as required by the spec), but before any side effects.
         if size.width == 0 || size.height == 0 || size.depth_or_array_layers == 0 {
             log::trace!("Ignoring write_texture of size 0");
             return Ok(());
@@ -963,11 +967,6 @@ impl Queue {
 
         self.device.check_is_valid()?;
 
-        if size.width == 0 || size.height == 0 || size.depth_or_array_layers == 0 {
-            log::trace!("Ignoring write_texture of size 0");
-            return Ok(());
-        }
-
         let mut needs_flag = false;
         needs_flag |= matches!(source.source, wgt::ExternalImageSource::OffscreenCanvas(_));
         needs_flag |= source.origin != wgt::Origin2d::ZERO;
@@ -1051,6 +1050,13 @@ impl Queue {
 
         let (selector, dst_base) = extract_texture_selector(&destination, &size, &dst)?;
 
+        // This must happen after parameter validation (so that errors are reported
+        // as required by the spec), but before any side effects.
+        if size.width == 0 || size.height == 0 || size.depth_or_array_layers == 0 {
+            log::trace!("Ignoring copy_external_image_to_texture of size 0");
+            return Ok(());
+        }
+
         let mut pending_writes = self.pending_writes.lock();
         let encoder = pending_writes.activate();