[PATCH] substr() returns false

Hi, Even though this is documented, it is strange behaviour: If the from parameter to substr() is at, or past, the end of the input string, the function returns false. The function is documented as string substr ( string string, int start [, int length]) IMHO substr() should either 1) be changed to do like Perl, which returns an error only if start is _beyond_ the end (not _at_): (from http://www.perldoc.com/perl5.6/pod/func/substr.html) my $null = substr $name, 6, 2; # returns '' (no warning) my $oops = substr $name, 7; # returns undef, with warning 2) be changed to return an empty string, if start is either at or beyond the end of the input string. I have attached patches for both solutions. If you don't change it to be like Perl, I think it should be noted in the documentation (as with chop()). If, on the other hand, it _is_ changed to behave like Perl, I think it should be emphasized that you are not guaranteed that the result is a string, because this will cause (eg. has caused us) problems when using the result as part of the $data array to PEAR DB::execute(). Happy hacking, Morten -- Morten Poulsen <morten-Qg2caEh8@afdelingp.dk> http://www.afdelingp.dk/

--- php-4.3.4-orig/ext/standard/string.c Mon Sep 29 04:23:52 2003 +++ php-4.3.4/ext/standard/string.c Wed Nov 19 14:18:08 2003 @@ -1679,7 +1679,11 @@ } } - if (f >= Z_STRLEN_PP(str)) { + /* if "from" position is beyond the end of the string, emit a warning + * and return false + */ + if (f > Z_STRLEN_PP(str)) { + php_error_docref(NULL TSRMLS_CC, E_WARNING, "Second argument has to be less than or equal the length of the first argument"); RETURN_FALSE; } --- php-4.3.4-orig/ext/standard/string.c Mon Sep 29 04:23:52 2003 +++ php-4.3.4/ext/standard/string.c Wed Nov 19 12:14:41 2003 @@ -1679,8 +1679,11 @@ } } + /* if "from" position is past the end of the string, return an empty + * string + */ if (f >= Z_STRLEN_PP(str)) { - RETURN_FALSE; + RETURN_STRING("", 1); } if ((f + l) > Z_STRLEN_PP(str)) {