PNMDataset False Positive

[rsoconnor]

GDAL tried to open up an ENVI file as a PNMDataset incorrectly and subsequently crashed in the GDALOpen function. It crashed in the "isspace" function because an assertion failed in pnmdataset.cpp

Admittedly this is a rare occurance and only happened once after opening up thousands of ENVI files.

The PNMDataset::Identify function may need to be more strict in its verification of files types.

My short term solution was just to deregister the PNM driver.

[rouault]

Could you possibly attach your ENVI file, or just the few first bytes ?

[rouault]

I've looked at the code and fixed a potential buffer overflow in case of bad PNM file, in r13655 in trunk and in r13656 in branches/1.5.

Hum, I'm just realizing it does not help for the PNMDataset::Identify function

[rsoconnor]

Replying to rouault:

Could you possibly attach your ENVI file, or just the few first bytes ?

Attached is the first 4k of the image file and the original ENVI header file.

[rouault]

I've fixed inverted logical tests in PNM identify that also help fixing this bug. Commited in trunk in r13663, in branches/1.5 in r13664, and the two fixes in branches/1.4 in r13665