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They call me "LoadPicture Lippert"

  • Artigo

As
promised, my least customer impactful bug ever. "urn:schemas-microsoft-com:office:office" />

VBScript
version 1.0 was written by one of the VB compiler devs, one of those uber-productive
guys who implements compilers on the weekend for fun. It
was implemented and tested extremely rapidly, and as a result, a few of the less important
methods in the VB runtime were not ported to the VBScript runtime. My
first task as a full timer at Microsoft was to add the missing functions to VBScript
2.0.

On
August 5th, 1996, I implemented LoadPicture, which, as you might imagine, extracts
a picture from a storage. Here's a scrap
of the code I wrote:

IDispatch
* pdisp;

// [...
open storage and stream ...]

hresult
= OleLoadPicture( pstream, 0, TRUE, IID_IPicture, (void **)&pdisp );

Did
I mention that I'd been writing COM code for all of two weeks at the time?

There's
a boneheaded bug there. I'm asking for
an IPicture and
assigning the result to an IDispatch. This
is going to crash and burn the moment anyone tries to call any method on that picture
object because the vtable is going to be completely horked.
I've violated one of the Fundamental Rules of COM. The fact that this bad code
shipped to customers indicates that:

*
Most seriously, I did not adequately test it before I checked it in

*
my mentors did not adequately review the code

*
the test team did not adequately test it before it shipped to customers

Those
are all bad, and I am happy to say that today we are much, much more hard-core about
peer-reviewing, self-testing, buddy-testing, and tester-testing code before it goes
to customers than we were seven years ago.

But
there is a silver lining of a sort -- obviously no one at Microsoft bothered
to run this code after I wrote it. But neither
did any customers. We didn't get
a bug report on this thing until February
of 1998. This thing was in the wild
for almost a year and a half before someone noticed that it was completely, utterly
broken! No one really cared.

The
next day the name plate on my office door said "LoadPicture Lippert". Ha
ha ha, very funny guys.

Comments

  • Anonymous
    September 23, 2003
    chuckles That is a great story. I do remember when those functions were added, and looking them over in the new docs, thinking that it must mean there was going to be support in the language for dynamically creating images. I also clearly recall finishing reading and concluding that I couldn't think of anything actually useful to do with that function in VBScript.So, that's the question - is there anything useful you can actually do with that OlePicture, even if the code had been flawless?
  • Anonymous
    September 24, 2003
    Not receiving bug reports is hardly evidence that no one used the code. When I try something that crash & burn, I usually assume that I'm doing something wrong. (Ok, ok, I try to assume) Without the source code to verify the bug, it's easier to assume I'm too dumb to understand correct usage.
  • Anonymous
    September 24, 2003
    > is there anything useful you can actually do with that OlePicture, even if the code had been flawless?Not really. You can't use it in "HTML" IE for security reasons, and why would you want to in WSH or ASP? That leaves "HTA" IE, but IE already has the ability to display pictures.
  • Anonymous
    September 25, 2003
    LoadPicture is useful for other hosts (or trusted web pages) where you are using ActiveX controls (such as an ImageList) that need to get their images as IOlePictureDisps (or whatever the interface is called). There are regular requests for it to be implemented in JScript -- http://groups.google.com/groups?q=LoadPicture+JScript
  • Anonymous
    September 29, 2003
    I find it ironic that you consider smart pointer evil, and still your most famous bug is exactly the kind of problem that smart pointers are designed to prevent.Are you also using ::CoCreateInstance() instead of CComPtr::CreateInstance()? If yes, are you sure your IIDs and pointer types match everywhere?
  • Anonymous
    October 01, 2003
    The comment has been removed
  • Anonymous
    October 13, 2009
    So this is an old thread, but I actually have found a use for LoadPicture. I am implementing it as vbscript to replace an old .bat file. My boss wants me to spruce it up. Im trying to load a company logo onto a msgbox. Ah well, someday....