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| author | Paul Eggert | 2011-06-16 14:25:42 -0700 |
|---|---|---|
| committer | Paul Eggert | 2011-06-16 14:25:42 -0700 |
| commit | 393d71f34cd42b77afe78fbd174f2b1377182232 (patch) | |
| tree | bb4efa252030d2a65cbf521bf603e9bc403c7c16 /src/buffer.h | |
| parent | 0cca0a78a4ee6b761c2fd91ee5a6628f23e3368c (diff) | |
| parent | 4847e3f0a94e3f24b40b060af528cf4b51d788c5 (diff) | |
| download | emacs-393d71f34cd42b77afe78fbd174f2b1377182232.tar.gz emacs-393d71f34cd42b77afe78fbd174f2b1377182232.zip | |
Improve buffer-overflow checking (Bug#8873).
Diffstat (limited to 'src/buffer.h')
| -rw-r--r-- | src/buffer.h | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/src/buffer.h b/src/buffer.h index dc1d62beb00..a13351b5ea6 100644 --- a/src/buffer.h +++ b/src/buffer.h | |||
| @@ -309,8 +309,10 @@ while (0) | |||
| 309 | 309 | ||
| 310 | /* Maximum number of bytes in a buffer. | 310 | /* Maximum number of bytes in a buffer. |
| 311 | A buffer cannot contain more bytes than a 1-origin fixnum can represent, | 311 | A buffer cannot contain more bytes than a 1-origin fixnum can represent, |
| 312 | nor can it be so large that C pointer arithmetic stops working. */ | 312 | nor can it be so large that C pointer arithmetic stops working. |
| 313 | #define BUF_BYTES_MAX min (MOST_POSITIVE_FIXNUM - 1, min (SIZE_MAX, PTRDIFF_MAX)) | 313 | The ptrdiff_t cast ensures that this is signed, not unsigned. */ |
| 314 | #define BUF_BYTES_MAX \ | ||
| 315 | (ptrdiff_t) min (MOST_POSITIVE_FIXNUM - 1, min (SIZE_MAX, PTRDIFF_MAX)) | ||
| 314 | 316 | ||
| 315 | /* Return the address of byte position N in current buffer. */ | 317 | /* Return the address of byte position N in current buffer. */ |
| 316 | 318 | ||