detect common issues in JOSM overpass querries, like overpass turbo

[mkoniecz]

What steps will reproduce the problem?

1. write query that outputs JSON, not XML
2. use query to download data in JOSM
3. become confused by "line 1 column 1: content is not allowed in prolog" error message

What is the expected result?

JOSM behaves like overpass turbo that on Export to JOSM in this situation shows

It looks like if this query will not return OSM data in XML format with metadata. Editors like JOSM require the data to be in that format, though.

overpass turbo can help you to correct the query by choosing "repair query" below.

What happens instead?

"line 1 column 1: content is not allowed in prolog" error message

Please provide any additional information below. Attach a screenshot if possible.

IRC snippet from #osm:

[17:43] <moltonel> Howdy, is there a know issue with download-from-overpass feature in JOSM ? I'm getting a "line 1 column 1: content is not allowed in prolog" error message for a query straight out of the wizard. Using josm 13265.
[17:44] <MK> moltonel: can you post link to query?
[17:45] <moltonel> http://overpass-turbo.eu/s/v5G
[17:45] <MK> moltonel: what happens if you select export and "load data into an OSM editor: JOSM"?
[17:46] <maxerickson> moltonel: get rid of the out:json, josm is rejecting the download.
[17:46] <moltonel> maxerickson: MK: thanks, that was it.

I also was bitten by this issue before.

URL:http://josm.openstreetmap.de/svn/trunk
Repository:UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Last:Changed Date: 2017-12-31 03:09:43 +0100 (Sun, 31 Dec 2017)
Build-Date:2017-12-31 02:33:46
Revision:13265
Relative:URL: ^/trunk

Identification: JOSM/1.5 (13265 en) Linux Ubuntu 16.04.3 LTS
Memory Usage: 322 MB / 869 MB (171 MB allocated, but free)
Java version: 1.8.0_151-b12, Oracle Corporation, Java HotSpot(TM) 64-Bit Server VM
Screen: :0.0 1920x1080
Maximum Screen Size: 1920x1080

Plugins:
+ OpeningHoursEditor (33876)
+ buildings_tools (33735)
+ continuosDownload (68)
+ imagery_offset_db (33774)
+ reverter (33865)
+ todo (30303)

Last errors/warnings:
- W: No configuration settings found.  Using hardcoded default values for all pools.

[mkoniecz]

overpass turbo checks: ​https://github.com/tyrasd/overpass-turbo/blob/b788464a8ac25cfb032e6316164efaafbb6232b2/js/ide.js#L2283

en localization for error messages: ​https://github.com/tyrasd/overpass-turbo/blob/bee1f04c33fb111485c805874a54b4905a9f2a77/locales/en.json#L242