AK: Calculate the chunk index correctly in DuplexMemoryStream.

asynts · awesomekling · commit 049f709d0b86 · 2020-09-11T16:07:45.000+02:00
diff --git a/AK/MemoryStream.h b/AK/MemoryStream.h
@@ -232,7 +232,7 @@ class DuplexMemoryStream final : public DuplexStream {
     {
         size_t nread = 0;
         while (bytes.size() - nread > 0 && m_write_offset - m_read_offset - nread > 0) {
-            const auto chunk_index = (m_read_offset - m_base_offset) / chunk_size;
+            const auto chunk_index = (m_read_offset - m_base_offset + nread) / chunk_size;
             const auto chunk_bytes = m_chunks[chunk_index].bytes().slice(m_read_offset % chunk_size).trim(m_write_offset - m_read_offset - nread);
             nread += chunk_bytes.copy_trimmed_to(bytes.slice(nread));
         }

Original file line number	Diff line number	Diff line change
`@@ -232,7 +232,7 @@ class DuplexMemoryStream final : public DuplexStream {`
`232`	`232`	`{`
`233`	`233`	`size_t nread = 0;`
`234`	`234`	`while (bytes.size() - nread > 0 && m_write_offset - m_read_offset - nread > 0) {`
`235`		`- const auto chunk_index = (m_read_offset - m_base_offset) / chunk_size;`
	`235`	`+ const auto chunk_index = (m_read_offset - m_base_offset + nread) / chunk_size;`
`236`	`236`	`const auto chunk_bytes = m_chunks[chunk_index].bytes().slice(m_read_offset % chunk_size).trim(m_write_offset - m_read_offset - nread);`
`237`	`237`	`nread += chunk_bytes.copy_trimmed_to(bytes.slice(nread));`
`238`	`238`	`}`