#9 segfault attempting to read record

[John Navratil]

I'm using pxlib.0.6.3 with PHP's paradox extension. This problem occured with 0.6.1, as well. My apologies if this is a problem with the PHP extension, but there has been no response to the PECL bug #10258 which I submitted almost a year ago.

Script to open and read a paradox DB file generates a segmentation fault when attempting to read a record. This appears to be related to some object initialization as I am able to successfully process this file using other scripts, quite easily. In fact, it was a bit of a challenge to preserve the error as I was stripping the script for a manageable example.

In the attached code the error appears if the paradoxOpen2() function is used, but does not if the in-line object open code is used.

The segFault occurs in the call:

return(p->px_stream->seek(p, p->px_stream, offset, whence));

occurring at line 151 of px_io.c The argument values in my test example were:

p:9bf861c stream:9bf0064 offset:2048 whence:0

My supposition is that something corrupted the stream pointer.

At some point in my experimentation, I received the message "PHP Fatal error: paradox_db::get_record(): Could not fseek start of first data block.", but was unable to reproduce that error. It may be a clue.

I could provide you with the 'STOCKLOT.DB' file, but observed this error on each of several files I have.

((( PS: It appears that a debug statement:

fprintf(stderr, "datablock position = %d\n", position);

may have been inadvertantly left at line 538 of px_head.c )))

[John Navratil]

Error example PHP script