From 368a1ded01c8c72de742ba7a4bf6edb27df8c67b Mon Sep 17 00:00:00 2001
From: desertwitch <24509509+desertwitch@users.noreply.github.com>
Date: Fri, 12 Sep 2025 16:27:59 +0200
Subject: [PATCH] fix: return nil ptr on error and safeguard embedding nil ptrs
 in returns

Signed-off-by: desertwitch <24509509+desertwitch@users.noreply.github.com>
---
 sort_generic.go         | 1 +
 sort_ordered.go         | 3 +++
 sort_sorttype_legacy.go | 4 ++++
 sort_strings.go         | 3 +++
 4 files changed, 11 insertions(+)

diff --git a/sort_generic.go b/sort_generic.go
index bdfbb01..d9d8ac3 100644
--- a/sort_generic.go
+++ b/sort_generic.go
@@ -164,6 +164,7 @@ func Generic[E any](input <-chan E, fromBytes FromBytesGeneric[E], toBytes ToByt
 		s.mergeErrChan <- err
 		close(s.mergeErrChan)
 		close(s.mergeChunkChan)
+		return nil, s.mergeChunkChan, s.mergeErrChan
 	}
 	return s, s.mergeChunkChan, s.mergeErrChan
 }
diff --git a/sort_ordered.go b/sort_ordered.go
index 25a0057..055c167 100644
--- a/sort_ordered.go
+++ b/sort_ordered.go
@@ -69,6 +69,9 @@ func (s *OrderedSorter[T]) toBytesOrdered(d T) ([]byte, error) {
 func Ordered[T cmp.Ordered](input <-chan T, config *Config) (*OrderedSorter[T], <-chan T, <-chan error) {
 	orderedSorter := newOrderedSorter[T]()
 	s, output, errChan := Generic(input, orderedSorter.fromBytesOrdered, orderedSorter.toBytesOrdered, cmp.Compare, config)
+	if s == nil {
+		return nil, output, errChan
+	}
 	orderedSorter.GenericSorter = *s
 	return orderedSorter, output, errChan
 }
diff --git a/sort_sorttype_legacy.go b/sort_sorttype_legacy.go
index 84f49da..629c2db 100644
--- a/sort_sorttype_legacy.go
+++ b/sort_sorttype_legacy.go
@@ -77,6 +77,10 @@ func New(input <-chan SortType, fromBytes FromBytes, lessFunc CompareLessFunc, c
 	compareGeneric := makeCompareSortType(lessFunc)
 
 	genericSorter, output, errChan := Generic(input, fromBytesGeneric, sortTypeToBytes, compareGeneric, config)
+	if genericSorter == nil {
+		return nil, output, errChan
+	}
+
 	s := &SortTypeSorter{GenericSorter: *genericSorter}
 	return s, output, errChan
 }
diff --git a/sort_strings.go b/sort_strings.go
index ef4251f..b7b670d 100644
--- a/sort_strings.go
+++ b/sort_strings.go
@@ -28,6 +28,9 @@ func toBytesString(s string) ([]byte, error) {
 // This function provides backward compatibility with the legacy string-specific API.
 func Strings(input <-chan string, config *Config) (*StringSorter, <-chan string, <-chan error) {
 	genericSorter, output, errChan := Generic(input, fromBytesString, toBytesString, cmp.Compare, config)
+	if genericSorter == nil {
+		return nil, output, errChan
+	}
 	s := &StringSorter{GenericSorter: *genericSorter}
 	return s, output, errChan
 }