437047 - cannot paste data from other application if target is not text/plain or html

Status: VERIFIED FIXED

(Core :: Widget, defect)

Description

[arno renevier]

Hi,
I'm trying to paste data from another application. Foreign application is gtk. Data is gchar*, and target is a custom one.

So, when trying to paste to mozilla, by calling clipboard.getData from javascript my data is packed in a two-bytes nsISupportsString (in nsPrimitiveHelpers::CreatePrimitiveForData).

So, I can get the data from javascript by unpacking with a custom function. But problem is: if length of data is odd, I don't get the last byte. That's because in nsPrimitiveHelpers::CreatePrimitiveForData, primitive->SetData(Substring(start, start + (aDataLen / 2))); does not take the last character if length is odd.

I'll attach a patch that seems to fix the problem. Unfortunately, I could not think of a test because when copying data from mozilla, it is internaly transformed into two-bytes nsISupportsString. So, I would need to run an external program to make a testcase.

Comment 1

[Al]

same as bug 428096?

Comment 2

[arno renevier]

Oups, I believed I had attached a patch. Sorry for the delay then.

No, it's not the same as bug 428096. problems arrives if you want to paste data to mozilla with a flavor gecko does not know of.

Comment 3

[arno renevier]

Attachment: adds two extra bytes to data string if datalen is odd

Comment 4

[Henrik Skupin [:whimboo][⌚️UTC+1]]

Arno, you should ask for review.

Comment 5

[Michael Ventnor]

Comment on attachment 332989 [details] [diff] [review]
adds two extra bytes to data string if datalen is odd

Whoa...xpwidgets? Definitely roc's forte, not mine.

Comment 6

[Robert O'Callahan (:roc) (email my personal email if necessary)]

Doesn't this mean we read an uninitialized byte when aDataLen is odd?

Comment 7

[arno renevier]

yes, may be I should set last byte to null, but I read http://developer.mozilla.org/en/docs/XPCOM:Strings and did not found or understood how to do.

Comment 8

[Robert O'Callahan (:roc) (email my personal email if necessary)]

When aDataLen is odd you might need to copy data to a temporary buffer and append a null byte to that.

Comment 9

[arno renevier]

Attachment: patch v2

Comment 10

[arno renevier]

I don't known if it's better to use calloc, or malloc + setting last byte to null.

Comment 11

[Robert O'Callahan (:roc) (email my personal email if necessary)]

Use nsAutoArrayPtr here to avoid having to call free explicitly, and just set the last byte to zero.

+        const PRUnichar* start = (const PRUnichar*)buffer;

Can you change these to reinterpret_cast<> while you're here? Thanks.

Comment 12

[arno renevier]

Attachment: patch v3

Comment 13

[Benjamin Smedberg]

Pushed to mozilla-central: https://hg.mozilla.org/mozilla-central/index.cgi/rev/357e923405af

Comment 14

[Henrik Skupin [:whimboo][⌚️UTC+1]]

Arno, can you verify the fix with an official nightly please? That would be helpful.

Comment 15

[arno renevier]

seems to work fine with latest firefox nightly

Comment 16

[Henrik Skupin [:whimboo][⌚️UTC+1]]

Marking verified based on comment 15.

Arno, is this Linux only or could it also happen on other platforms / OS?

Comment 17

[arno renevier]

I suppose problem can be seen on other systems, but I'm really not sure.

Comment 18

[Henrik Skupin [:whimboo][⌚️UTC+1]]

Martijn, would it be good to have an automated test here? At least a simple testcase would be great so we could use it as Litmus test. With such a testcase we could also test the fix on all other systems.

Comment 19

[arno renevier]

problem is that you need to have an external program (to put stuff in the clipboard) to trigger that behaviour.

Comment 20

[Martijn Wargers (dead)]

It would always be good to have an automated test for this. But I guess it might be very difficult to achieve this, like Arno said (I don't know this code at all).
A litmus-test would be fine too.

Comment 21

[arno renevier]

Attachment: copy stuff in clipboard.

I don't know how that could be useful, but here is the code I use to put stuff in the clipboard. It uses gtk.

Comment 22

[arno renevier]

Attachment: copy stuff from clipboard (javascript)

And here is the javascript snippet I use to read stuff from clipboard.