colexec: incorrectly setting batch length before restoring the selection vector in CASE operator

[cockroach-teamcity]

This issue was autofiled by Sentry. It represents a crash or reported error on a live cluster with telemetry enabled.

Sentry link: https://sentry.io/organizations/cockroach-labs/issues/2520160489/?referrer=webhooks_plugin

Panic message:

error.go:88: unexpected error from the vectorized engine: ×
--
*barriers.barrierError
*errutil.withPrefix: unexpected error from the vectorized engine (1)
error.go:88: *withstack.withStack (top exception)
*assert.withAssertionFailure
*colexecerror.notInternalError
(check the extra data payloads)

Stacktrace (expand for inline code snippets):

cockroach/pkg/sql/colexecbase/colexecerror/error.go

Lines 87 to 89 in 402d4f6

	// unexpected.
	retErr = errors.NewAssertionErrorWithWrappedErrf(err, "unexpected error from the vectorized engine")
	}

in pkg/sql/colexecbase/colexecerror.CatchVectorizedRuntimeError.func1
/usr/local/go/src/runtime/panic.go#L678-L680 in runtime.gopanic
/usr/local/go/src/runtime/panic.go#L74-L76 in runtime.goPanicIndex

cockroach/pkg/col/coldata/bytes.go

Lines 79 to 81 in 402d4f6

	for j := 1; j <= n; j++ {
	if b.offsets[j] > prev {
	prev = b.offsets[j]

in pkg/col/coldata.(*Bytes).UpdateOffsetsToBeNonDecreasing

cockroach/pkg/col/coldata/batch.go

Lines 263 to 265 in 402d4f6

	for _, bytesVecIdx := range m.bytesVecIdxs {
	m.b[bytesVecIdx].Bytes().UpdateOffsetsToBeNonDecreasing(maxIdx + 1)
	}

in pkg/col/coldata.(*MemBatch).SetLength

cockroach/pkg/sql/colexec/case.go

Lines 254 to 256 in 402d4f6

	// Restore the original state of the buffered batch.
	c.buffer.batch.SetLength(origLen)
	c.buffer.batch.SetSelection(origHasSel)

in pkg/sql/colexec.(*caseOp).Next

cockroach/pkg/sql/colexec/operator.go

Lines 457 to 459 in 402d4f6

	func (e *BatchSchemaSubsetEnforcer) Next(ctx context.Context) coldata.Batch {
	b := e.input.Next(ctx)
	if b.Length() == 0 {

in pkg/sql/colexec.(*BatchSchemaSubsetEnforcer).Next

cockroach/pkg/sql/colexec/buffer.go

Lines 61 to 63 in 402d4f6

	func (b *bufferOp) advance(ctx context.Context) {
	b.batch = b.input.Next(ctx)
	b.rewind()

in pkg/sql/colexec.(*bufferOp).advance

cockroach/pkg/sql/colexec/case.go

Lines 112 to 114 in 402d4f6

	func (c *caseOp) Next(ctx context.Context) coldata.Batch {
	c.buffer.advance(ctx)
	origLen := c.buffer.batch.Length()

in pkg/sql/colexec.(*caseOp).Next

cockroach/pkg/sql/colexec/simple_project.go

Lines 123 to 125 in 402d4f6

	func (d *simpleProjectOp) Next(ctx context.Context) coldata.Batch {
	batch := d.input.Next(ctx)
	if batch.Length() == 0 {

in pkg/sql/colexec.(*simpleProjectOp).Next

cockroach/pkg/sql/colexec/hash_aggregator.go

Lines 221 to 223 in 402d4f6

	}
	op.bufferingState.pendingBatch, op.bufferingState.unprocessedIdx = op.input.Next(ctx), 0
	n := op.bufferingState.pendingBatch.Length()

in pkg/sql/colexec.(*hashAggregator).Next

cockroach/pkg/sql/colexec/routers.go

Lines 723 to 725 in 402d4f6

	func (r *HashRouter) processNextBatch(ctx context.Context) bool {
	b := r.input.Next(ctx)
	n := b.Length()

in pkg/sql/colexec.(*HashRouter).processNextBatch

cockroach/pkg/sql/colexec/routers.go

Lines 658 to 660 in 402d4f6

	processNextBatch := func() {
	done = r.processNextBatch(ctx)
	}

in pkg/sql/colexec.(*HashRouter).Run.func1.1

cockroach/pkg/sql/colexecbase/colexecerror/error.go

Lines 90 to 92 in 402d4f6

	}()
	operation()
	return retErr

in pkg/sql/colexecbase/colexecerror.CatchVectorizedRuntimeError

cockroach/pkg/sql/colexec/routers.go

Lines 696 to 698 in 402d4f6

	if err := colexecerror.CatchVectorizedRuntimeError(processNextBatch); err != nil {
	r.cancelOutputs(ctx, err)

in pkg/sql/colexec.(*HashRouter).Run.func1

cockroach/pkg/sql/colexecbase/colexecerror/error.go

Lines 90 to 92 in 402d4f6

	}()
	operation()
	return retErr

in pkg/sql/colexecbase/colexecerror.CatchVectorizedRuntimeError

cockroach/pkg/sql/colexec/routers.go

Lines 654 to 656 in 402d4f6

	// well for more fine-grained control of error propagation.
	if err := colexecerror.CatchVectorizedRuntimeError(func() {
	r.input.Init()

in pkg/sql/colexec.(*HashRouter).Run

cockroach/pkg/sql/colflow/vectorized_flow.go

Lines 658 to 660 in 402d4f6

	runRouter := func(ctx context.Context, _ context.CancelFunc) {
	router.Run(logtags.AddTag(ctx, "hashRouterID", strings.Join(streamIDs, ",")))
	}

in pkg/sql/colflow.(*vectorizedFlowCreator).setupRouter.func1

cockroach/pkg/sql/colflow/vectorized_flow.go

Lines 1199 to 1201 in 402d4f6

	go func() {
	run(ctx, flowCtxCancel)
	if wg != nil {

in pkg/sql/colflow.(*vectorizedFlowCreatorHelper).accumulateAsyncComponent.func1.1
/usr/local/go/src/runtime/asm_amd64.s#L1356-L1358 in runtime.goexit

pkg/sql/colexecbase/colexecerror/error.go in pkg/sql/colexecbase/colexecerror.CatchVectorizedRuntimeError.func1 at line 88
/usr/local/go/src/runtime/panic.go in runtime.gopanic at line 679
/usr/local/go/src/runtime/panic.go in runtime.goPanicIndex at line 75
pkg/col/coldata/bytes.go in pkg/col/coldata.(*Bytes).UpdateOffsetsToBeNonDecreasing at line 80
pkg/col/coldata/batch.go in pkg/col/coldata.(*MemBatch).SetLength at line 264
pkg/sql/colexec/case.go in pkg/sql/colexec.(*caseOp).Next at line 255
pkg/sql/colexec/operator.go in pkg/sql/colexec.(*BatchSchemaSubsetEnforcer).Next at line 458
pkg/sql/colexec/buffer.go in pkg/sql/colexec.(*bufferOp).advance at line 62
pkg/sql/colexec/case.go in pkg/sql/colexec.(*caseOp).Next at line 113
pkg/sql/colexec/simple_project.go in pkg/sql/colexec.(*simpleProjectOp).Next at line 124
pkg/sql/colexec/hash_aggregator.go in pkg/sql/colexec.(*hashAggregator).Next at line 222
pkg/sql/colexec/routers.go in pkg/sql/colexec.(*HashRouter).processNextBatch at line 724
pkg/sql/colexec/routers.go in pkg/sql/colexec.(*HashRouter).Run.func1.1 at line 659
pkg/sql/colexecbase/colexecerror/error.go in pkg/sql/colexecbase/colexecerror.CatchVectorizedRuntimeError at line 91
pkg/sql/colexec/routers.go in pkg/sql/colexec.(*HashRouter).Run.func1 at line 697
pkg/sql/colexecbase/colexecerror/error.go in pkg/sql/colexecbase/colexecerror.CatchVectorizedRuntimeError at line 91
pkg/sql/colexec/routers.go in pkg/sql/colexec.(*HashRouter).Run at line 655
pkg/sql/colflow/vectorized_flow.go in pkg/sql/colflow.(*vectorizedFlowCreator).setupRouter.func1 at line 659
pkg/sql/colflow/vectorized_flow.go in pkg/sql/colflow.(*vectorizedFlowCreatorHelper).accumulateAsyncComponent.func1.1 at line 1200
/usr/local/go/src/runtime/asm_amd64.s in runtime.goexit at line 1357

Tag	Value
Cockroach Release	v20.2.12
Cockroach SHA:	402d4f6
Platform	linux amd64
Distribution	CCL
Environment	v20.2.12
Command	server
Go Version	``
# of CPUs
# of Goroutines