potlatch creates invalid ways having only one node or multiple consecutive identical nodes #2501
Comments
Author: Richard Steps to reproduce please or I'll close this. |
Author: xylome this is a serious issue, please investigate this further! i don't have the slightest idea how this could be reproduced (i'm using JOSM as editor), but there are hundreds of those ways produced each day. |
Author: Richard Replying to [comment:2 xylome]:
Then I would ask you to open Potlatch for once in your life, and try. I have a million and one people asking me to do things; if you want your particular itch scratched then you'll need to at least do a bit of the work yourself. |
Author: xylome let me first say, that i appreciate your work very much and that potlatch does a very good jobs in giving people a jumpstart into osm. but it's not an itch of mine and yes i have no idea how this erroneous behaviour can be reproduced. i'm only seeing the results. it's a data integrity problem potlatch is producing here. maybe you could do a validation of the ways potlatch produces before they get uploaded. |
Author: Richard That's kind of the problem, though - as far as I know (I haven't looked at that code for a while) Potlatch does validate this. There's a method in way.as called removeDuplicates that makes sure that if, for example, you have a way ABCB and C is removed, one of the Bs will be removed too. This is why I'm keen to get a reproducible test case. |
Author: xylome for me it seems as if it happens, when people try to doubleclick to end drawing a way. most of the multiple identical nodes are on the end of a way and do not seem to be the result of a deletion of a node in the middle of a way. |
Author: xylome some of the ways are one-node-ways. it seems as if the user deletes one node of a two-node-way. the result should be, that also the affected way should be deleted then. the last remaing node should also be deleted if it is no member of another way or relation. |
Author: Richard The hint about it being the end of a way is really helpful - thank you. I'll have a look next week once I've got a bit more free time. |
Author: Ilis I have such errors using Potlatch. I dont no steps to reproduce, but it often happens when I have add point on crossing ways with Shift+Click. |
Author: katzlbt I would bet it can be done by linking the way to itself and deleting the node before. |
Author: NE2 Is this possibly related to http://trac.openstreetmap.org/ticket/2700 ? |
Author: koenigl[at]fs.tum.de Replying to [comment:1 Richard]:
Im not sure whether this is related to the problem discussed here (This is my second night with OSM ... ;-) but I just made the following observation in Potlatch: After heavy load due to zooming out to far (during which the OS and Flash plugin raised message boxes concering non-reacting applications and Flash scripts, respectively) apparently keyboard input to Potlatch stopped working. At least, Potlatch did not seem to react to neither ESC, nor DEL, nor R. As a consequence, the only possibility (I knew about) to cancel the drawing of a new way that was started unintentionally was to click the first endpoint again, resulting in a single point (black-lined green circle in Potlatch) and maybe a way containing that point (that would have to be invisible). I left one of these near lat=48.06028, lon=11.47237, tagged fixme. Behavior of Potlatch returned to normal after navigating (via the Browser) to map and then back to edit. ... hope that helps ... |
Author: Richard It's not related afaik. |
Author: Sanderd17 Sometimes, I see black dots. When you click on one, it always produces a street, even if you just want to select the dot. One of those dots are the traffic lights in http://www.openstreetmap.org/edit?lat=50.94854&lon=3.13093&zoom=17 . Hope that has something to do with the bug. If not, it's another bug. Sander |
Author: Sanderd17 OK, all black dots are traffic lights, but I still don't get why these dots are treated in an other way than normal nodes. |
Author: skippern[at]gimnechiske.org I had this bug occur doing import from scripts, it might be that this bug is not related to Potlatch at all. In my case it was DXF files converted to OSM XML and than split in layers. I discovered the connection between the scripts and multiple node bug when installing Validator plugin in JOSM. I have not checked if there are other activities behind the other occurrences of this bug. I have done my best to clean out these multiple nodes. There are no one-node ways in my import as far as I can tell. |
Author: mcld xybot is asking me to give you "hints about how the bug can be recreated" (from http://www.openstreetmap.org/history?bbox=-3.46892%2C51.19971%2C-3.44732%2C51.20855). I didn't know I was creating these problems (pretty new to osm) so I'm not sure what to say. I'm just manually adding paths on my mac laptop (firefox 3.6.3), although I'm using a graphics tablet to draw them so that may be the issue? e.g. some small movements while clicking? That's pretty much all I can say at the moment, but feel free to ask me questions. |
Author: NE2 I created this node when joining two crossing ways (shift-click): http://www.openstreetmap.org/browse/node/740243448 No, I don't have directions to reproduce. But if you go to http://www.openstreetmap.org/edit?lat=41.9022109&lon=-87.6717511&zoom=18&way=24095618 and join this way to each cross street in succession, you'll sometimes get this. It happens annoyingly infrequently. |
Author: mrpulley Here's another one that I inadvertently caused: When I created the offending node (http://www.openstreetmap.org/browse/node/764758248 ), I was creating a new way (http://www.openstreetmap.org/browse/way/61134997 ). I can't remember if I created the new way, aligned it, then created the junction node (then removing the ends), or if I just clicked on the pre-existing way to create the node. Either way, the duplicate nodes only existed (until fixed by Xybot) on the pre-existing way. I did not split the way and then join the two ends up, so there is no obvious way for me to create the multiple consecutive nodes. I was using Potlatch 1.4, MacOS 10.5, using Firefox. Can't remember the Flash version (I'm at work at the moment). Hope this helps. |
Author: mrpulley I'm using Firefox 3.6.3, flash version 10.0 r45. |
Author: mrpulley I've just inadvertently added another one - multiple consecutive identical nodes. Changeset: http://www.openstreetmap.org/browse/changeset/5543616 I've just manually fixed it http://www.openstreetmap.org/browse/changeset/5544198 . |
Author: phillipsjk Replying to [comment:1 Richard]:
I noticed that when joining ways, the editor prompts you to click to join when the cursor is over the node of the old way. After clicking, the user is asked to repeat the process even if the ways are already joined at that node. After clicking a second time, the user is no longer prompted. I tried to reproduce the problem with http://www.openstreetmap.org/browse/changeset/5668901 (save, rather than live edit.) Potlatch 1.4 (save en) |
Author: phillipsjk By accident, if discovered that xybot cleaned up after me: http://www.openstreetmap.org/browse/way/46785224/history I created that node by sift-clicking where the two ways joined. I may have used Ctrl-click first, but that appeared to have no effect. Attempt to reproduce by joining ends appear to have failed: http://www.openstreetmap.org/browse/changeset/5804821 Attempt to reproduce by joining nodes on a self-overlapping way failed (potlatch does not appear to support that. Created two overlapping ways: http://www.openstreetmap.org/browse/changeset/5804908 Success!: Created two redundant nodes on lower way; I dragged the connection around to ensure the two ways were connected (should check if bug is present without dragging, but I won't). http://www.openstreetmap.org/browse/way/77908536 Summary: reproduced the "potlatch creates invalid ways having ... multiple consecutive nodes" part of bug. |
Author: Richard Good news but I'm having awful trouble parsing any of those sentences! And I can't really see what those ways are because you've deleted them. Could you provide simple instructions to reproduce, along the lines of "click to start a new way, draw some points, double-click to end" etc. etc.? |
Author: phillipsjk Steps to reproduce:
To view the Deleted way history:
No, the deleted way is not rendered :P |
Author: Richard Very strange. I can't reproduce that at all, either on my test box or the live site. The ways always come out perfectly formed when I follow those instructions, whether in save or live mode, with thin ways or thick ways, whatever I try. (And yes I do know how to view deleted ways, obviously, it's just that I find using the data browser a PITA. :) ) |
Author: phillipsjk Did you turn on extra debugging? when trying to reproduce the error again, I got an error message I couldn't read completely due to a character set I don't understand. Possible things to check: B: Does moving the node have an effect?
Server said:
{Stroke from center to lower left}{Short stroke from upper right to center;longer stroke from center to lower right}{vertical stroke on upper left; 'J' on opposing side}{medium horizontal stroke near top with uptick;long horizontal stroke slightly below first;Both preceding strokes top a 'J'}{long horizontal stroke}{two ticks in upper left; 'J' starting at right below half-way point}{Backward 'E'}{single tick in uper left; 'J' starting at right below half-way point}{Vertical stroke on left with tick at bottom; two short horizontal strokes on right}{Upside-down 'Y'; two medium horizontal strokes above center; short vertical stroke on left edge of horizontal strokes}{Man with ladder on left}{'L' with bottom portion up-turned}{Downstroke with clockwise curl at bottom; two medium horizontal strokes}{'L' with bottom portion up-turned}{Vertical stroke from left of center to bottom left; short horizontal stoke through downstroke; Short horizontal stoke center-right; medium horizontal stroke lower right}{small circle lower left}{white space}{''}{'/';Vertical stoke on right}{downstroke with clockwise curl at bottom; single medium horizontal stoke near top} (newline) {'2';'5';'5'}{man}{'7' wearing flat, broad hat; long horizontal stoke at center}{downstroke with uptick on left; floating tick upper left; upside-down 'Y' on right}{small up-side-down 'Y', set inside upstroke-horizontal stroke-downstroke}{Short horizonatal stroke upper left;'C';tick just above center-right}{Lambda symbol}{'J' on left; horizontal stroke-downstroke with tick}{'L' with uptutned bottom}{top horizontal stoke-'C'}{'<'}{vertical stoke from top left of center to bottom left; short horizontal stroke through top of downstroke; 3 short horizontal strokes on right}{vertical stroke ending in small 'c'; medium horizontal stroke above-center}{meduim vertical stroke with uptick top-left;tick on right above center}{small circle lower left} (newline)
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Author: phillipsjk Oops: Forgot to mention: I am in the habit of [C]losing the changeset before saving. This is an attempt to force the comment dialog box to appear. |
Author: Richard No, I haven't changed anything. |
Author: phillipsjk I am going to have to echo 'NE2' and says I can no longer reliably reproduce the bug. My latest attempt to follow my reproduction steps yielded correct results as far as I can tell: http://www.openstreetmap.org/browse/changeset/5833987 I have noticed that my mouse does not always debounce properly under load, but I was unable to induce errors by triple-clicking, or by running Prime95 in background with default blended test settings. Firefox was using hardly any CPU time at all, even with Prime95 +19 niced (maximum; lowest priority). I had to stop prime95 to get the editor to draw the map (maybe I wasn't patient enough; but interrupts (disk paging) were using 0% of the CPU at the time). I have confirmed the CPU and memory appear to be working correctly. I ran Prime95 with blended test, but reduced memory footprint (230MB instead of 760MB) for over 24 hours. No errors were reported. Potlatch was able to edit normally without disk paging. Because the mersenne.org download page was not working, I had to get the windows version from a mirror (ran it under wine). |
Author: phillipsjk note: just checked the 'top' man page: what I was calling 'interrupts' was actually 'iowait'; "Amount of time the CPU has been waiting for I/O to complete." (probably DMA transfers). With DMA enabled, interrupts rarely use more than a few % of CPU time. I suppose it is possible the 'niced' prime95 was using 90% of the CPU time because firefox was spending 90% of the time waiting on the disk :P |
Author: phillipsjk I again failed to reproduce the problem with my reproduction steps. (http://www.openstreetmap.org/browse/changeset/5888031) The only thing I can think of that I changed was the deletion of Flash cookies. I am using a linux version of flash that allows you to drop it into the mozilla pluging directory of a single user without affecting the whole system. The files I deleted are stored in:
I may need to resort to white-box debugging to track this down. I have never coded in flash in part because I oppose it in principle. I am using Potlatch instead of JOSM because I am lazy (still don't have my workstation "just so"; don't want to lose track of 20GB.). The original report says that Potlach was the editor most commonly implicated. Which editor is most popular? Could the problem be server-side, but Potlatch gets implicated because it interacts with the server more often? |
Author: ghia I analysed a changeset Other case is Weird is also that in this changeset several version of the same object are present. |
Author: leighghunt[at]gmail.com Hi - in OSM changeset 6379862 for way 85321659 (http://www.openstreetmap.org/browse/way/85321659/history) there was the following comment:
I edited these polygons first in Potlatch as three polygons, and then merged them into one polygon in JOSM, so this was probably user error, rather than a bug in Potlatch. Cheers, |
Author: nakor.wp[at]gmail.com This is very easy to reproduce in Potlatch 2: select a node at the end of a way, then double-click on it -> the node is now duplicated in the way. In Potlatch 1, use the same process but it only "works"if you double click on a node after it turned blue. See changeset http://www.openstreetmap.org/browse/changeset/6568527 (P2) and http://www.openstreetmap.org/browse/changeset/6568770 (P1) where I was able to do it several times. |
Author: sdoerr So could a developer perhaps 'accept' this supposedly 'new' bug report and see if they can fix it? |
Author: cucafera Changeset: http://www.openstreetmap.org/browse/changeset/7929894 Hope it helps. Alfonso. |
Author: bwnz Yes, using Potlatch. Just had a look at history on a portion of map I edited 3 Jan (#10278715). Pretty sure no other changes have been made anywhere near here since BUT multiple instances of xybot claiming to be removing multiple consecutive identical nodes. Either message is indicating checking for problem rather than fixing, or problem may be introduced in data storage or manipulation after changeset saved. Which? |
Author: Nick Austin I've actully seen this bug several times while editing. In all cases I was just editing normally - adding points to the end of a way. The same as I've done many times previously and many times since without the bug appearing. In order words I don't have a sequence that reproduces the bug because it's just something that happens randomly. However on several occasions I was able to use Z to undo the problem and this has given clues as to what happened. I actually see two variants of this problem one of which xybot can catch and the other just results in a very odd shapped way. I'll explain both as best as I can in case either is of help. Variant 1: Variant 2: |
Author: bill42 I just noticed this on a way I edited yesterday: I remember joining nodes that were consecutive on the street. Steps to reproduce: Here is the Way "B" from my attempt to reproduce. |
Author: stevage Fixed here: systemed/potlatch2#65 What's going on: when you merge B2 with B3, you end up with one node, but it's repeated in the node list for the way. In other situations, this would be legitimate, say if there was another couple of nodes between them: you'd have a sort of loop half way through the way. Anyway, I've explicitly added a check for this situation. That addresses the specific issue raised by bill42. The rest of this thread was TL;DR - please reopen if I missed something that is still pertinent. |
Author: Oli-Wan Sorry to disappoint you, but the bug has not been fixed, or at least not completely - Potlatch still creates ways with consecutive identical nodes. Just one example out of many (created in April of 2013): http://www.openstreetmap.org/browse/way/215524538 [[BR]] |
Author: iandees Cleaning aging tickets. If someone can nail down a reproducible problem feel free to reopen this in the potlatch2 component. |
Reporter: xylome
[Submitted to the original trac issue database at 12.11am, Wednesday, 25th November 2009]
a way with only one node makes no sense: http://wiki.openstreetmap.org/wiki/Data_Primitives#Way
a way can have identical nodes (e.g. circular ways), but there is no reason for having an identical node succeeding itself within a way.
please refer to the history of the ways in changeset http://www.openstreetmap.org/browse/changeset/3210744. in almost all cases potlatch was the editor in question generating those errors, before xybot repaired the errors.
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