Document why size < 0 can happen

marcelm · marcelm · commit 4c3c9083aad4 · 2023-09-29T01:05:17.000+02:00
diff --git a/Modules/_io/bytesio.c b/Modules/_io/bytesio.c
@@ -493,6 +493,7 @@ _io_BytesIO_peek_impl(bytesio *self, Py_ssize_t size)
     n = self->string_size - self->pos;
     if (size < 1 || size > n) {
         size = n;
+        /* size can be negative after truncate() */
         if (size < 0) {
             size = 0;
         }

Original file line number	Diff line number	Diff line change
`@@ -493,6 +493,7 @@ _io_BytesIO_peek_impl(bytesio *self, Py_ssize_t size)`
`493`	`493`	`n = self->string_size - self->pos;`
`494`	`494`	`if (size < 1 \|\| size > n) {`
`495`	`495`	`size = n;`
	`496`	`+ /* size can be negative after truncate() */`
`496`	`497`	`if (size < 0) {`
`497`	`498`	`size = 0;`
`498`	`499`	`}`