diff options
author | nobu <nobu@b2dd03c8-39d4-4d8f-98ff-823fe69b080e> | 2011-03-02 14:20:06 +0000 |
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committer | nobu <nobu@b2dd03c8-39d4-4d8f-98ff-823fe69b080e> | 2011-03-02 14:20:06 +0000 |
commit | cddcffb8f9dd015650b2ac02235bfe39261989f9 (patch) | |
tree | d327758d47d6a93d6f9c20d07477be7b3b0a2c89 /string.c | |
parent | e1e8297a76cbe7918458cb37043ad498228c6139 (diff) | |
download | ruby-cddcffb8f9dd015650b2ac02235bfe39261989f9.tar.gz |
* string.c (str_byte_substr): return nil for negative length.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@31007 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Diffstat (limited to 'string.c')
-rw-r--r-- | string.c | 56 |
1 files changed, 29 insertions, 27 deletions
@@ -3990,35 +3990,37 @@ rb_str_setbyte(VALUE str, VALUE index, VALUE value) static VALUE str_byte_substr(VALUE str, long beg, long len) { - char *p, *s = RSTRING_PTR(str), *e = s + RSTRING_LEN(str); - VALUE str2; - if (beg > RSTRING_LEN(str)) return Qnil; - if (beg < 0) { - beg += RSTRING_LEN(str); - if (beg < 0) return Qnil; - } - if (beg + len > RSTRING_LEN(str)) - len = RSTRING_LEN(str) - beg; - if (len <= 0) { - len = 0; - p = 0; - } - else - p = s + beg; + char *p, *s = RSTRING_PTR(str); + long n = RSTRING_LEN(str); + VALUE str2; - if (len > RSTRING_EMBED_LEN_MAX && beg + len == RSTRING_LEN(str)) { - str2 = rb_str_new4(str); - str2 = str_new3(rb_obj_class(str2), str2); - RSTRING(str2)->as.heap.ptr += RSTRING(str2)->as.heap.len - len; - RSTRING(str2)->as.heap.len = len; - } - else { - str2 = rb_str_new5(str, p, len); - rb_enc_cr_str_copy_for_substr(str2, str); - OBJ_INFECT(str2, str); - } + if (beg > n || len < 0) return Qnil; + if (beg < 0) { + beg += n; + if (beg < 0) return Qnil; + } + if (beg + len > n) + len = n - beg; + if (len <= 0) { + len = 0; + p = 0; + } + else + p = s + beg; - return str2; + if (len > RSTRING_EMBED_LEN_MAX && beg + len == n) { + str2 = rb_str_new4(str); + str2 = str_new3(rb_obj_class(str2), str2); + RSTRING(str2)->as.heap.ptr += RSTRING(str2)->as.heap.len - len; + RSTRING(str2)->as.heap.len = len; + } + else { + str2 = rb_str_new5(str, p, len); + rb_enc_cr_str_copy_for_substr(str2, str); + OBJ_INFECT(str2, str); + } + + return str2; } static VALUE |