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author | Ludovic Courtès <ludo@gnu.org> | 2014-01-17 18:18:41 +0100 |
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committer | Ludovic Courtès <ludo@gnu.org> | 2014-01-17 18:18:41 +0100 |
commit | 3ff8a9d6ff9c8b9f3be7c03b624b3042bb61079f (patch) | |
tree | cb1a10d7e00265489058baac1e0414c611e18e2a | |
parent | 802a25b1ed5c738aa5f9d3d01f33eb89b22afd1b (diff) | |
download | guile-3ff8a9d6ff9c8b9f3be7c03b624b3042bb61079f.tar.gz |
Arrange so that 'file-encoding' does not truncate the encoding name.
Fixes <http://bugs.gnu.org/16463>.
Reported by Sree Harsha Totakura <sreeharsha@totakura.in>.
* libguile/read.c (ENCODING_NAME_MAX_SIZE): New macro.
(SCM_ENCODING_SEARCH_SIZE): Change to 500 + ENCODING_NAME_MAX_SIZE.
(scm_i_scan_for_encoding): Return NULL if there's less than
ENCODING_NAME_MAX_SIZE bytes once "coding: *" has been read.
* test-suite/tests/coding.test ("line
comment")["http://bugs.gnu.org/16463"]: New test.
-rw-r--r-- | libguile/read.c | 30 | ||||
-rw-r--r-- | test-suite/tests/coding.test | 10 |
2 files changed, 31 insertions, 9 deletions
diff --git a/libguile/read.c b/libguile/read.c index f7edc4f8a..419ad1276 100644 --- a/libguile/read.c +++ b/libguile/read.c @@ -2046,11 +2046,20 @@ scm_get_hash_procedure (int c) } } -#define SCM_ENCODING_SEARCH_SIZE (500) +/* Maximum size of an encoding name. This is a bit more than the + longest name listed at + <http://www.iana.org/assignments/character-sets> ("ISO-2022-JP-2", 13 + characters.) */ +#define ENCODING_NAME_MAX_SIZE 20 -/* Search the first few hundred characters of a file for an Emacs-like coding - declaration. Returns either NULL or a string whose storage has been - allocated with `scm_gc_malloc ()'. */ +/* Number of bytes at the beginning or end of a file that are scanned + for a "coding:" declaration. */ +#define SCM_ENCODING_SEARCH_SIZE (500 + ENCODING_NAME_MAX_SIZE) + + +/* Search the SCM_ENCODING_SEARCH_SIZE bytes of a file for an Emacs-like + coding declaration. Returns either NULL or a string whose storage + has been allocated with `scm_gc_malloc'. */ char * scm_i_scan_for_encoding (SCM port) { @@ -2109,8 +2118,8 @@ scm_i_scan_for_encoding (SCM port) if ((pos = strstr(pos, "coding")) == NULL) return NULL; - pos += strlen("coding"); - if (pos - header >= SCM_ENCODING_SEARCH_SIZE || + pos += strlen ("coding"); + if (pos - header >= SCM_ENCODING_SEARCH_SIZE || (*pos == ':' || *pos == '=')) { pos ++; @@ -2119,10 +2128,17 @@ scm_i_scan_for_encoding (SCM port) } /* skip spaces */ - while (pos - header <= SCM_ENCODING_SEARCH_SIZE && + while (pos - header <= SCM_ENCODING_SEARCH_SIZE && (*pos == ' ' || *pos == '\t')) pos ++; + if (pos - header >= SCM_ENCODING_SEARCH_SIZE - ENCODING_NAME_MAX_SIZE) + /* We found the "coding:" string, but there is probably not enough + room to store an encoding name in its entirety, so ignore it. + This makes sure we do not end up returning a truncated encoding + name. */ + return NULL; + /* grab the next token */ encoding_start = pos; i = 0; diff --git a/test-suite/tests/coding.test b/test-suite/tests/coding.test index a8a415ff4..b57ef7da7 100644 --- a/test-suite/tests/coding.test +++ b/test-suite/tests/coding.test @@ -1,6 +1,6 @@ ;;;; coding.test --- test suite for coding declarations. -*- mode: scheme -*- ;;;; -;;;; Copyright (C) 2011, 2013 Free Software Foundation, Inc. +;;;; Copyright (C) 2011, 2013, 2014 Free Software Foundation, Inc. ;;;; ;;;; This library is free software; you can redistribute it and/or ;;;; modify it under the terms of the GNU Lesser General Public @@ -101,4 +101,10 @@ (pass-if-equal "second line, whitespace, nl" "ISO-8859-1" - (scan-coding "\n; coding: iso-8859-1 \n"))) + (scan-coding "\n; coding: iso-8859-1 \n")) + + (pass-if-equal "http://bugs.gnu.org/16463" + ;; On Guile <= 2.0.9, this would return "ISO-8". + "ISO-8859-1" + (scan-coding (string-append (make-string 485 #\space) + "; coding: ISO-8859-1")))) |