Stop Loss value being (still sometimes) erased when reached

[DannyIbo]

Expected behavior

The SLs should be displayed in the trade list (within the result stats) whenever they are set (according to the strategy).

Code sample

from backtesting import Backtest, Strategy
from backtesting.test import GOOG
from backtesting.lib import crossover

class Strat(Strategy):
    def init(self):
        pass
    def next(self):
        if self.position:
            pass
        else:
            price = self.data.Close[-1]
            self.buy(size = 1, sl = price - 10, tp = price + 20)
        
bt = Backtest(GOOG, Strat, cash=10_000)
output = bt.run()
display(output._trades.iloc[30:33])
bt.plot()

Actual behavior

When I get the list of the trades, some of them are unprovided with the SL. This seems to happen only for the trades being closed BELOW the set SL.

This issue seems to be an unfixed part of the bug report #1288 by @xyffar.

Additional info, steps to reproduce, full crash traceback, screenshots

Software versions

• backtesting.__version__: 0.6.5
• pandas.__version__: 2.3.3
• numpy.__version__: 1.26.2
• bokeh.__version__: 3.8.1
• OS: Linux 6.14.0-36-generic x86_64