| Summary: | ASTERISK-04048: ast_copy_string cuts off the last character when passing in a size | ||
| Reporter: | jshugart (jshugart) | Labels: | |
| Date Opened: | 2005-05-03 15:02:53 | Date Closed: | 2008-01-15 15:33:04.000-0600 |
| Priority: | Major | Regression? | No |
| Status: | Closed/Complete | Components: | Core/General |
| Versions: | Frequency of Occurrence | ||
| Related Issues: | |||
| Environment: | Attachments: | ( 0) set_destination.patch | |
| Description: | ast_copy_string(temp, "abc", 3); will fill temp with "ab" and drop the "c". I am compiling with gcc 3.2.3. | ||
| Comments: | By: Diego Ercolani (dercol) 2005-05-03 17:24:51 seem a problem of set_destination routine in chan_sip.c. My patch should resolve. By: Kevin P. Fleming (kpfleming) 2005-05-03 19:47:36 First: that behavior is exactly what is expected from ast_copy_string(). It always null-terminates the output buffer, unlike strncpy(). If you pass it a string containing three characters (which is actually four bytes long) and an output buffer size of '3', the last character of the string will be replaced with a null byte, so that the output will be null-terminated. Second: there _was_ a bug in ast_copy_string() when it was used to copy substrings (when the source string had more characters than needed to be copied). That is now corrected. Third: the semantic differences between strncpy() and ast_copy_string() when used to copy substrings are significant enough that each usage needs to be individually reviewed and corrected (or left alone to use strncpy()). I did not do that adequately when I did the ast_copy_string() conversion in chan_sip.c yesterday, which led to multiple places where strings were not copied properly. I believe those are now corrected. I'm sorry for the trouble... however, that is the reason why CVS HEAD is for testing, not production :-) Occasionally we will all make mistakes. By: Digium Subversion (svnbot) 2008-01-15 15:33:04.000-0600 Repository: asterisk Revision: 5561 U trunk/channels/chan_sip.c U trunk/utils.c ------------------------------------------------------------------------ r5561 | kpfleming | 2008-01-15 15:33:03 -0600 (Tue, 15 Jan 2008) | 2 lines fix breakage when ast_copy_string is used to copy substrings (bug ASTERISK-4048, but a different fix) ------------------------------------------------------------------------ http://svn.digium.com/view/asterisk?view=rev&revision=5561 | ||