Some images make Emacs behave strangely

Some images make Emacs behave strangely

[Lars Magne Ingebrigtsen]

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Here's an image from the pheedo web tracking ad thingie whatever:

[larsi@quimbies ~/pgnus]$ file /tmp/a
/tmp/a: GIF image data, version 89a, 1 x 1

However:

(image-size (create-image "/tmp/a") t)
=> (30 . 30)

And inserting that image into the buffer yields an empty 30x30 box:

(put-image (create-image "/tmp/a") (point))

In addition, the rest of the text in entire buffer starts shaking and
shivering, and the cursor disappears.

So something is just not right, I think.

Here's the GIF in question:


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-- 
(domestic pets only, the antidote for overdose, milk.)
  larsi@gnus.org * Lars Magne Ingebrigtsen

Re: Some images make Emacs behave strangely

[Chong Yidong]

Lars Magne Ingebrigtsen <larsi@gnus.org> writes:

> Here's an image from the pheedo web tracking ad thingie whatever:
>
> [larsi@quimbies ~/pgnus]$ file /tmp/a
> /tmp/a: GIF image data, version 89a, 1 x 1
>
> However:
>
> (image-size (create-image "/tmp/a") t)
> => (30 . 30)
>
> And inserting that image into the buffer yields an empty 30x30 box:
>
> (put-image (create-image "/tmp/a") (point))

Emacs fails to load the image, because DGifSlurp returns GIF_ERROR when
we try to load its contents into memory.  I dunno what else we could do
to avoid failing (or why the GIMP seems to be able to handle this gif).

If I create a 1x1 gif file using the GIMP, Emacs can read it perfectly.

Re: Some images make Emacs behave strangely

[Lars Magne Ingebrigtsen]

Chong Yidong <cyd@stupidchicken.com> writes:

> Emacs fails to load the image, because DGifSlurp returns GIF_ERROR when
> we try to load its contents into memory.  I dunno what else we could do
> to avoid failing (or why the GIMP seems to be able to handle this gif).

Shouldn't `create-image' just return nil in that case, instead of
returning something that acts as an image?  I mean, that what
`create-image' does when you point it at something that isn't an image
at all, and this case should be no different...

-- 
(domestic pets only, the antidote for overdose, milk.)
  larsi@gnus.org * Lars Magne Ingebrigtsen

Re: Some images make Emacs behave strangely

[David Kastrup]

Chong Yidong <cyd@stupidchicken.com> writes:

> Lars Magne Ingebrigtsen <larsi@gnus.org> writes:
>
>> Here's an image from the pheedo web tracking ad thingie whatever:
>>
>> [larsi@quimbies ~/pgnus]$ file /tmp/a
>> /tmp/a: GIF image data, version 89a, 1 x 1
>>
>> However:
>>
>> (image-size (create-image "/tmp/a") t)
>> => (30 . 30)
>>
>> And inserting that image into the buffer yields an empty 30x30 box:
>>
>> (put-image (create-image "/tmp/a") (point))
>
> Emacs fails to load the image, because DGifSlurp returns GIF_ERROR when
> we try to load its contents into memory.  I dunno what else we could do
> to avoid failing (or why the GIMP seems to be able to handle this gif).

The question is not how to avoid failing, but how make Emacs accept
failure.  Emacs goes into a busy, display-thrashing loop making it
rather unresponsive.

-- 
David Kastrup

Re: Some images make Emacs behave strangely

[Andreas Schwab]

Chong Yidong <cyd@stupidchicken.com> writes:

> Emacs fails to load the image, because DGifSlurp returns GIF_ERROR when
> we try to load its contents into memory.  I dunno what else we could do
> to avoid failing (or why the GIMP seems to be able to handle this gif).

GIMP also complains about the invalid image.  It is missing the
terminate record (try appending a semicolon to the file).

Andreas.

-- 
Andreas Schwab, schwab@linux-m68k.org
GPG Key fingerprint = 58CA 54C7 6D53 942B 1756  01D3 44D5 214B 8276 4ED5
"And now for something completely different."