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| author | Phil Turnbull <philipturnbull@github.com> | 2018-02-16 13:25:56 -0500 |
|---|---|---|
| committer | Phil Turnbull <philipturnbull@github.com> | 2018-02-20 12:25:04 -0500 |
| commit | e489ba4ccb92af53ea823223481005384fad5e14 (patch) | |
| tree | c9c703979f23d0ec54c237cb9846f6f05907c26c /src/render.c | |
| parent | a5c83d7a426bda38aac838f9815664f6189d3404 (diff) | |
Check for empty buffer when rendering
For empty documents, `->size` is zero so
`renderer.buffer->ptr[renderer.buffer->size - 1]` will cause an out-of-bounds
read. Empty buffers always point to the global `cmark_strbuf__initbuf` buffer
so we read `cmark_strbuf__initbuf[-1]`.
Diffstat (limited to 'src/render.c')
| -rw-r--r-- | src/render.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/src/render.c b/src/render.c index 20dca5f..5abd52e 100644 --- a/src/render.c +++ b/src/render.c @@ -171,7 +171,7 @@ char *cmark_render(cmark_node *root, int options, int width, } // ensure final newline - if (renderer.buffer->ptr[renderer.buffer->size - 1] != '\n') { + if (renderer.buffer->size == 0 || renderer.buffer->ptr[renderer.buffer->size - 1] != '\n') { cmark_strbuf_putc(renderer.buffer, '\n'); } |