Summary:ASTERISK-12969: KEYPADHASH returns incorrect values
Reporter:Manuel Meitinger (meitinger)Labels:
Date Opened:2008-10-26 11:40:30Date Closed:2008-10-26 15:12:48
Versions:Frequency of
Description:I don't know how others ever managed to get KEYPADHASH working properly, but it should be impossible. The input string is traversed and each char is checked with strchr in an if-elseif-elseif-...-else fashion, checking for the null-terminator at the final else (and breaking the loop if it is encountered). However, if I may quote the manpage of strchr:

"The terminating null character is considered to be part of the string; therefore if c is `\0', the functions locate the terminating `\0'."

So once the null-terminator is encountered, the first strchr (which checks for key #2) always matches, so if one executed e.g.


the returned value is 83782... followed by whatever is behind the null-terminator until the length of the output buffer is reached. Usually this is 22222222222... because more '\0' are encountered.
Of course, this can easily be fixed. Just move the null-terminator-check from the final else to the first if.
Comments:By: Digium Subversion (svnbot) 2008-10-26 15:12:46

Repository: asterisk
Revision: 152059

U   branches/1.4/funcs/func_strings.c

r152059 | seanbright | 2008-10-26 15:12:45 -0500 (Sun, 26 Oct 2008) | 7 lines

Since passing \0 as the second argument to strchr is valid (and will
match the trailing \0 of a string) we need to check that first, otherwise
we end up with incorrect results.  Fix suggested by reporter.

(closes issue ASTERISK-12969)
Reported by: meitinger