Check Write err value.

Author: icedream

CHANGELOG.md

@@ -8,6 +8,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Changed
 * Updated license to reflect current year (2025)
 
+### Fixed
+* Fix writer failure not being returned from `Patch` methods.
+
 ## [1.0.2] - 2025-02-27
 ### Changed
 * Update kingpin v2 import path.

doc.go

@@ -29,7 +29,10 @@ func Patch(oldReader io.Reader, newWriter io.Writer, patchReader io.Reader) (err
 	bz2Reader := bzip2.NewReader(patchReader)
 
 	err = native.Patch(oldBytes, newBytes, bz2Reader)
+	if err != nil {
+		return err
+	}
 
-	newWriter.Write(newBytes)
+	_, err = newWriter.Write(newBytes)
 	return
 }

patch/patch.go

@@ -28,7 +28,10 @@ func Patch(oldReader io.Reader, newWriter io.Writer, patchReader io.Reader, newS
 	newBytes := make([]byte, newSize)
 
 	err = native.Patch(oldBytes, newBytes, oldReader)
+	if err != nil {
+		return err
+	}
 
-	newWriter.Write(newBytes)
+	_, err = newWriter.Write(newBytes)
 	return
 }