Check errors

sign/pdfbyterange.go

@@ -6,7 +6,9 @@ import (
 )
 
 func (context *SignContext) updateByteRange() error {
-	context.OutputBuffer.Seek(0, 0)
+	if _, err := context.OutputBuffer.Seek(0, 0); err != nil {
+		return err
+	}
 	output_file_size := int64(context.OutputBuffer.Buff.Len())
 
 	// Calculate ByteRange values to replace them.
@@ -29,17 +31,23 @@ func (context *SignContext) updateByteRange() error {
 	// Make sure our ByteRange string didn't shrink in length.
 	new_byte_range += strings.Repeat(" ", len(signatureByteRangePlaceholder)-len(new_byte_range))
 
-	context.OutputBuffer.Seek(0, 0)
+	if _, err := context.OutputBuffer.Seek(0, 0); err != nil {
+		return err
+	}
 	file_content := context.OutputBuffer.Buff.Bytes()
 
-	context.OutputBuffer.Write(file_content[:context.ByteRangeStartByte])
+	if _, err := context.OutputBuffer.Write(file_content[:context.ByteRangeStartByte]); err != nil {
+		return err
+	}
 
 	// Write new ByteRange.
 	if _, err := context.OutputBuffer.Write([]byte(new_byte_range)); err != nil {
 		return err
 	}
 
-	context.OutputBuffer.Write(file_content[context.ByteRangeStartByte+int64(len(new_byte_range)):])
+	if _, err := context.OutputBuffer.Write(file_content[context.ByteRangeStartByte+int64(len(new_byte_range)):]); err != nil {
+		return err
+	}
 
 	return nil
 }