[MC-133503] Control settings from 1.12.2 can get completely lost when upgrading to 1.13

The bug

When upgrading from 1.12.2 to 1.13 with the attached options.txt file, all control settings are lost. Usually, the control options are converted correctly.

Apparently, this happens when the APPS key is used for any control, but I'm not too sure about that.

To reproduce

Create a new profile with its game directory in an empty folder and launch 1.12.2 with it.
Close the game and replace the options.txt file with the one I attached to this report.
Change the profile so that it launches 1.13-pre8 instead. Launch 1.13-pre8 using that profile.
Notice that all the control settings are gone.

Error message

Something went wrong upgrading!
java.lang.StringIndexOutOfBoundsException: String index out of range: -1
	at java.lang.String.substring(String.java:1919)
	at aar.a(SourceFile:24)
	at aar$$Lambda$791/835175041.apply(Unknown Source)
	at java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:193)
	at java.util.Spliterators$ArraySpliterator.forEachRemaining(Spliterators.java:948)
	at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:512)
	at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:502)
	at java.util.stream.ReduceOps$ReduceOp.evaluateSequential(ReduceOps.java:708)
	at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
	at java.util.stream.ReferencePipeline.collect(ReferencePipeline.java:499)
	at aar.a(SourceFile:28)
	at aar$$Lambda$790/293786079.apply(Unknown Source)
	at java.util.Optional.map(Optional.java:215)
	at aar.a(SourceFile:20)
	at aar$$Lambda$789/761923430.apply(Unknown Source)
	at com.mojang.datafixers.Typed.lambda$updateCap$9(Typed.java:160)
	at com.mojang.datafixers.Typed$$Lambda$779/907089215.apply(Unknown Source)
	at com.mojang.datafixers.optics.Traversal$Instance$1.lambda$wander$0(Traversal.java:32)
	at com.mojang.datafixers.optics.Traversal$Instance$1$$Lambda$780/1957188885.apply(Unknown Source)
	at com.mojang.datafixers.util.Pair$Instance.traverse(Pair.java:81)
	at com.mojang.datafixers.optics.profunctors.TraversalP$1.lambda$wander$0(TraversalP.java:48)
	at com.mojang.datafixers.optics.profunctors.TraversalP$1$$Lambda$781/731584462.apply(Unknown Source)
	at com.mojang.datafixers.optics.Traversal$Instance$1.lambda$wander$0(Traversal.java:32)
	at com.mojang.datafixers.optics.Traversal$Instance$1$$Lambda$780/1957188885.apply(Unknown Source)
	at com.mojang.datafixers.optics.Traversal$Instance$1.lambda$wander$0(Traversal.java:32)
	at com.mojang.datafixers.optics.Traversal$Instance$1$$Lambda$780/1957188885.apply(Unknown Source)
	at com.mojang.datafixers.Typed.updateCap(Typed.java:160)
	at com.mojang.datafixers.Typed.update(Typed.java:134)
	at com.mojang.datafixers.Typed.update(Typed.java:129)
	at aar.a(SourceFile:19)
	at aar$$Lambda$493/885343736.apply(Unknown Source)
	at com.mojang.datafixers.DataFix.lambda$null$4(DataFix.java:74)
	at com.mojang.datafixers.DataFix$$Lambda$762/1293967722.apply(Unknown Source)
	at com.mojang.datafixers.functions.Comp.eval(Comp.java:27)
	at com.mojang.datafixers.functions.PointFreeFunction.lambda$null$0(PointFreeFunction.java:15)
	at com.mojang.datafixers.functions.PointFreeFunction$$Lambda$760/1251709638.apply(Unknown Source)
	at com.mojang.datafixers.FunctionType$$Lambda$623/1700123096.apply(Unknown Source)
	at com.mojang.datafixers.types.Type.capWrite(Type.java:153)
	at com.mojang.datafixers.types.Type.lambda$null$7(Type.java:144)
	at com.mojang.datafixers.types.Type$$Lambda$758/1290606579.apply(Unknown Source)
	at java.util.Optional.map(Optional.java:215)
	at com.mojang.datafixers.types.Type.lambda$readAndWrite$8(Type.java:143)
	at com.mojang.datafixers.types.Type$$Lambda$757/494367851.apply(Unknown Source)
	at java.util.Optional.flatMap(Optional.java:241)
	at com.mojang.datafixers.types.Type.readAndWrite(Type.java:142)
	at com.mojang.datafixers.DataFixerUpper.update(DataFixerUpper.java:78)
	at hk.a(SourceFile:493)
	at hk.a(SourceFile:489)
	at cfj.a(SourceFile:1042)
	at cfj.a(SourceFile:804)
	at cfj.<init>(SourceFile:377)
	at cfg.am(SourceFile:415)
	at cfg.a(SourceFile:377)
	at net.minecraft.client.main.Main.main(SourceFile:144)

I attached the full log.