Odd cgi.FieldStorage behavior

[Fred Murray]

Hi all,

When uploading a file ("input type=file"), FieldStorage usually
behaves correctly, but every once in a while (every couple days?), it
will suddenly start causing internal server errors. A look at the
apache (v. 2.0.44 on Linux) error log shows "premature end of script
headers" with no error messages from Python. After reloading the
browser about 10 times in a row, it will suddenly start working again.
Recently, when a series of these errors was occuring, I removed the
FieldStorage line from my program and it completed normally. When I
put the line back in again, the internal server errors resumed. Thus,
it seems that the bug is either in FieldStorage itself or in something
FieldStorage interacts with.

It seems odd that that there are no errors in the log from Python.
Does this mean the program is crashing before it can output a
traceback to stderr?

Cheers,
Fred

 

[Tim Roberts]

When uploading a file ("input type=file"), FieldStorage usually
behaves correctly, but every once in a while (every couple days?), it
will suddenly start causing internal server errors. A look at the
apache (v. 2.0.44 on Linux) error log shows "premature end of script
headers" with no error messages from Python. After reloading the
browser about 10 times in a row, it will suddenly start working again.
Recently, when a series of these errors was occuring, I removed the
FieldStorage line from my program and it completed normally. When I
put the line back in again, the internal server errors resumed. Thus,
it seems that the bug is either in FieldStorage itself or in something
FieldStorage interacts with.

It seems odd that that there are no errors in the log from Python.
Does this mean the program is crashing before it can output a
traceback to stderr?

It often means the script terminated normally without outputting any HTML,
or that you caught an error with a try/finally and didn't reraise the
error.