Hello Friends,
I've had this trouble before, and it was clouded by other issues when I posted about it in the past. But it continues to be a frustration, off and on.

Sometimes I cannot add a node by double-clicking on the path. When this happens, I cannot even select the segment on which I'm trying to add a node, by clicking on the segment. Typically I will resort to selecting each node individually (using Shift), then click the Add Nodes button. (But often this is not ideal, because I need to place the node carefully, and the Add Nodes button puts it in the middle of the segment.) And typically I will continue to work on my image. But the next time I try to add a node by double-clicking, it works beautifully, perfect, no problem. Then I might work for a while with no problems. But then it happens again.

I just can't sort out exactly what's causing this inability to add nodes by double-click or even select a segment by clicking on it. I try to look at everything which might cause this -- make sure the path is selected, make sure the Node tool is selected. What else can I look for, that might reveal more clues? Has anyone else noticed something like this?

Since it's been happening several times tonight, I think I'll try and collect some screen shots, the next time it happens. Maybe some of you can spot something I'm missing?

Oh maybe this is a clue. I don't remember how the pathes were created in the past. But tonight, I'm creating them with the paint bucket tool . Maybe it's a bug with this tool?

Can you all give me any guidance on this issue?
Thanks for your help

Ok, as I expected, it's happened again. Here's a link to the screen print:
http://img516.imageshack.us/img516/3483/inkss813fd4.png
I don't know why it does not show the cursor, but I put a red circle to show the area where I'm trying to put the node. You can see I'm using Node tool. And I'm trying to add a node by double-clicking the path whose fill is green. So just along the border between the green and the thin white sliver under the black line. (Well it's not exactly white, but I guess gray.)(I need a node there so I can drag the green to meet the black.) I'm definitely within the grab area, on the green but as close to the white as possible. You can see that the path is selected -- just barely, the dashed line can be seen just below the ruler.

Not 5 minutes ago I added a node to the exact same path using double-click. So I just can't figure out what's behind this....glitch? bug? problem.

Can anyone see any clues from the screen shot? Any info, at this point, would be helpful.
Thanks as always.

Sorry if this is a silly question, but are you sure there's a path there? Or is it just the edge of the fill on a non-closed path?

Thanks sas.
I'm pretty sure. The node to the right is smooth, to the left is cusp. Neither are end nodes, which I think means the path is closed (I made it with the paint bucket tool ). Also, I've added nodes to the same path already, and simply want to add another.

I have a little more info now. I wondered if the problem was with the double-click specifically, or something else. So I selected the black line which is a stroke on a separate path from the one filled with green (black stroke, no fill). Then I double-clicked on that path, and just as it should, created a new node right there! So it's not the double-click, there's something else.

[Edit -- Is there some way to show you the XML Editor? Like a screen shot, or is there some way to upload the file?]

I've experienced this bug a number of times when making knot diagrams, because I need to precisely place nodes as well. Sometimes parts of a path are just ignored for no apparent reason. The path will be selected, and while using the Node tool, the cursor changes from the thin arrow of the node tool cursor to include a grabbing hand whenever you're near the path. Well when this bug appears, you can follow the path with the mouse and see the cursor change from the grabbing hand arrow to the regular node tool arrow and back for specific small portions of a path. In those small portions you can't manipulate the path at all with the mouse: can't grab, can't add nodes. It's like Inkscape forgets part of the path is there.

I vaguely remember figuring out a way to work around the problem, but not what the actual work around was. And of course the bug is intermittent, and I can't get it to happen right now, so I can't test these ideas. Anyway, try these things brynn, one of them might work:

• Temporarily change the path's stroke width to a high value, like 100 px.
• Move one of the nodes on either side of the dead area very slightly to force Inkscape to recalculate the path.
• Duplicate the path and delete the original.

Let us know if one of them works.

If it occurs on specific areas of a path, I'd be curious to know if the area that doesn't work when double-clicking is effected when you zoom in and out. If not, I would then attempt to save the file, close Inkscape then reopen Inkscape and the file and see if that same area still cannot be double-clicked. If it can't, you might have a file the developers will be interested in seeing to examine what is going wrong.

Ah, but alas, I've had to close the image. So can't test out your suggestions at the moment.

micro, no, I did not experiment with zooming. But I certainly will, the next time it happens.

kelan, I haven't always noticed the little hand icon, but I do sometimes see it. So I will also be sure, the next time I encounter the problem, to experiment with moving the cursor along the path. What does that little hand icon signify, under normal circumstances?

In those small portions you can't manipulate the path at all with the mouse: can't grab, can't add nodes. It's like Inkscape forgets part of the path is there.

YES! That's exactly what happens. I can't even select the segment on which I want to add the node (except by selecting it's nodes individually).

As far as a workaround, I either select the 2 nodes defining the segment one at a time (using Shift) and then click the Add Nodes button (however, as we've said, that isn't always an option when exact placement of the node is an issue), or just go and work on some other part of the image, and when i come back to it, usually the problem does not occur. Otherwise, this

Move one of the nodes on either side of the dead area very slightly to force Inkscape to recalculate the path.

is probably the least disruptive. And especially because you can make note of the node's coordinates, to make sure you get it back exactly where it was before.

I wonder if zooming (as micro mentioned) would force this recalculation? Because that would surely be the best workaround.

kelan, is this a bug that's been reported? If not, shouldn't it be?

Well, thanks for everyone's comments. And especially kelan, I'm relieved it's not just me, or that I'm doing something wrong -- thanks for speaking up!

microUgly wrote:If it occurs on specific areas of a path, I'd be curious to know if the area that doesn't work when double-clicking is effected when you zoom in and out.

Zooming hasn't fixed it for me. Usually what happens is that at a low zoom level the affected area on the path is quite small. But when zooming in close, the dead area grows larger with the path. It's like this one specific section of the path is dead, no matter the zoom level.

brynn wrote:What does that little hand icon signify, under normal circumstances?

The regular node tool arrow switches to include a hand whenever you're near a selectable part of the path. I guess it's to signify that you can interact with the path at that point using the mouse. The fact that the cursor doesn't switch shows you that Inkscape doesn't recognize there is a path there for whatever reason.

brynn wrote:kelan, is this a bug that's been reported? If not, shouldn't it be?

I couldn't find any similar bug in launchpad, but I'm not going to report it until I can make it occur reliably. As a programmer, I've always been annoyed by reports for intermittent bugs, especially when there's no indication at all of what triggers this one.

As a programmer, I've always been annoyed by reports for intermittent bugs, especially when there's no indication at all of what triggers this one.

Yes, I can see where intermittent could be impossible to fix! Is there anything I can do to help with this? Like make note of the last few steps I took, just before it happens, for example? Or something else? I tend to be very detail oriented. Or is this gonna be over my head, and I should leave it for you pros to handle?

brynn wrote:Is there anything I can do to help with this? Like make note of the last few steps I took, just before it happens, for example? Or something else? I tend to be very detail oriented. Or is this gonna be over my head, and I should leave it for you pros to handle?

If you can get the bug to happen consistently, or even mostly consistently, by following the same steps, that's probably enough for a bug report.

Ok, I have another instance of this problem just now. So I've attempted to gather more info about it. Is it ok to use this thread to document info as I discover it? Or I guess maybe developers keep it to themselves until they have something substantial....? Well, just let me know if it's inappropriate. I want to share, because I may not really recognize the relevance of what I find.

Yes, I see what you mean about the little hand icon disappearing and reappearing, as I move the cursor along the path. In this instance, JUST before I noticed the problem, I was adjusting a node handle. My finger slipped off the mouse so the mouse dropped the handle. At that point, the node became unselected, and the handles were no longer visible.

Now, I don't think that dropping the handle caused the node and handles to be unselected. Because I think I tried to grab it again real quick, but was no longer close enough to it to grab it. So it registered a click, which caused the node to be unselected. That said, I'm not sure if either the dropped handle or weird little click could cause this problem. But just gathering info

Well, this may be something significant. Ok, let me upload a screen shot...linked here:
http://img167.imageshack.us/img167/9248 ... 508xf8.png

At 1st I thought I noticed that the grabbing hand was appearing in what would be the area between handles of adjacent nodes, if the handles were visible. So I slowly moved the cursor along the path, and noted the coordinates of the points where the grabbing hand appeared and disappeared. I thought those points were going to correspond to the ends of the handles, when I select a node to reveal the handles. But no, they do not correspond exactly, although some are very close. In the screen shot, I've put a pink/purple line to show where the hand appears (it's offset from the actual path, which of course is where the green meets the black line).

I also noticed that the hand always appears at and near the nodes. But interestingly, it's not always over the same distance along the path. For example, the hand appears approx 3 cursors' lengths away from the corner/cusp node (ignore the more horizontal part of the path along the top). But around the node to the right of the cusp, the hand appears just one cursor's length away from the node. I'm sorry the cursor doesn't appear in the screen shots, but I'm talking about the narrow black arrow, less the grabbing hand, for these very rough estimates. Then the hand appears about 2 cursors' length from the 3rd node.

The most significant info I've gleaned from this "exercise", IMO, is:
(1) The part of the path which is affected by this issue, is that defined by the node which was selected for the last change I made to the path, before the problem showed up. So it's just like under normal circumstances, when one selects a node, its handles, as well as the handles of the node on either side of the selected one, are revealed. The center node, that's selected in the screen shot, is the one whose handle I was moving, when my finger slipped off the mouse button. And the...dead zones(?!), the areas where the grabbing hand disappears, only occur in the segments to either side of that node. So I think that must help narrow down the source of the problem, ie - it's not totally random, as it has appeared until now. This info seems to point to the slipping of my finger off the mouse button and/or the weird click that followed (as I tried to re-grab the handle). However, it may be that the problem started earlier, but I hadn't noticed it. Maybe some developers would have other insights?

There are a couple of other thoughts I'm having about this, but haven't come up with a way of "testing":
(2) Could the coordinates I noted, that mark the points along the path where the grabbing hand appears and disappears, perhaps correspond to where node handles cross the path? Even at the maximum zoom, it's impossible to see.
(3) Or could it have something to do with the angle at which the handles lie?

I wonder if I save this image as it is at this moment, and upload a SVG, if the problem will still be evident?? Well, for me, opening a new instance of this same image does retain the problem, so let's try it. The pink/purple circle indicates the path you want to look for when you open the SVG. And you should be able to tell from the screen shot I linked above, the affected portion of the path. Try moving your cursor along the path, and note whether the grabbing hand comes and goes (roughly as indicated by the hot pink lines in the screen shot).

And here's a link to the SVG (no comments on the image as a whole please, it's just practice):
http://www.petaimg.com/uploads/1218895753.svg
[Edit - new link - http://www.petaimg.com/uploads/1219000554.svg]
If the problem is retained in the SVG, maybe someone else can learn more than I can.

And I haven't forgotten about micro's suggestion re zoom. The problem does not change or resolve when changing the zoom. Everything we've learned about the problem (won't double-click, single-click, highlight, grab the path, nothing) is consistent at several different zoom levels. However, as I think I mentioned, save, close and reopen does resolve the problem, at least temporarily. So the problem is not ready to be reported in that regard either.

And just some final few observations as I try to make the problem go away.
-- If a node is selected, and I click in one of the "dead zones" (where the grabbing hand does not show up), it unselects the node. But it does not select that segment. Same for double-click.
-- Selecting something else (the black line/path) and then reselecting the path in question, does not stop the problem.
-- Selecting a node or segment outside the affected area, but on the same path, no effect. And they're also unselected when I click in a dead zone.
-- Moving the handle of a node in the affected area, no change. Oh kelan, moving a node in the affected are does NOT resolve the issue, as you predicted it might!
-- Clicking in a non-dead zone in the affected area, does select the segment, but does not resolve the issue.
-- Changing the stroke width, as kelan suggested -- well the path doesn't have a stroke. And when I add a stroke to it, the problem is resolved. But once I go back to no stroke, the problem is the same. I wonder if this only occurs when a path has no stroke? I can't remember for certain, when this has happened before, whether I was using a stroke or not.
-- Duplicating the path, as kelan suggested, duplicates with the same problem. So I guess that's strike 3 for kelan's suggestions, sorry kelan. I certainly would be interested to hear any further thoughts you might have -- especially if you can open the SVG I uploaded, and play around with the problem.

Ok I've done as much as I can for now. Hopefully the problem will be retained in the SVG upload, so others can study it.

All best.

Hey, I think I know what it is!
In my last reply above, when I tested moving the node handles for its effect on the issue, I moved a node handle, but I tested on the other segment than the one I moved the handle. But looking at the same segment, if I move the handle so that it's not close to the path itself, the problem is resolved on that segment!

So could it be that having a node handle which lies actually on the path itself, is the cause of this problem?

Ah rats! That hypothesis is holding true on the image I'm working on, but I can't duplicate it in a brand new image

I just don't know where else to look for a cause, besides at the problem itself. What could be triggering this bug

The link the the SVG is incorrect or the file was removed.

??? I don't know what could be the problem. I'm sure I did everything right. But in any case, I uploaded again, and edited a new link into my message. For conventience, this the new link:
http://www.petaimg.com/uploads/1219000554.svg

Is this one working?

brynn wrote:Is this one working?

Nope. Is it working for you? Perhaps they are blocking me for some reason.

I don't have any problem downloading brynn's files.

The first one does exhibit the bug for me in Inkscape 0.46, but it works OK in a recent dev build. There have been big changes to the way paths are handled since 0.46 came out, so this bug could well have been fixed (perhaps accidentally).

There have been big changes to the way paths are handled since 0.46 came out, so this bug could well have been fixed (perhaps accidentally).

Awesome!