GUI trader error - tradingDetails.gain is null

[elexis]

In this svn game with r18586 I had selected at least one trade cart at minute 56 which repeated the following GUI error:

TypeError: tradingDetails.gain is null
  unitActions["setup-trade-route"].getActionInfo@gui/session/unit_actions.js:542:1
  getActionInfo@gui/session/input.js:230:8
  unitActions["setup-trade-route"].actionCheck@gui/session/unit_actions.js:560:8
  determineAction@gui/session/input.js:309:8
  updateCursorAndTooltip@gui/session/input.js:63:7
  onTick@gui/session/session.js:601:2
  __eventhandler642 (tick)@sn tick:0:1

This seems to be the same error as in #3277, however I can't reproduce it this way anymore. There was very likely a captured or destroyed market / dock involved though.

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Also the "Gain" tooltip sometimes shows an empty string, reproduce:

1. produce trade cart at market 1
2. right click market 2
3. right click market 1

the tooltips will show "Origin trade market. Gain: " and "Destination trade market. Gain: ".

[elexis]

Seems like the error can't be reproduced from a visual replay in perspective unfortunately.

[elexis]

alpha 20 replay where the bug occurs with 8 trade carts at min 47 after the two markets have been captured and deleted min 45. Reproducible by changing the perspective to the blue player, selecting the carts and hovering a new market.

[elexis]

Alpha 21 r18830 replay where that error occurs to some of my trade carts when they were idle in the bottom left corner of the map (f.e entity 46250)

[elexis]

Alpha 23 replay at #5127.

[Imarok]

Move tickets to In-game UI as UI & Simulation got some sub components.

[Silier]

Also the "Gain" tooltip sometimes shows an empty string, reproduce:

produce trade cart at market 1
right click market 2
right click market 1
the tooltips will show "Origin trade market. Gain: " and "Destination trade market. Gain: ".

This shows actual gain of the trader, not what trade gain of the route is in general. So it shows nothing as he has nothing at that point.