Animated Texture Interpolate causing crashes

Is not being able to specify the last index an intended feature it works if interpolate isn't true

I confirmed that this is reproducible and it's suppose to be able to work with the last index but, since it wasn't in order it seems to be crashing this is a bug

Can an admin please verify so it get's fixed test this on 1.12.2

Confirmed in 17w46a. No longer causes a game crash, but the texture doesn't work, and the same general error is output into the log while loading resources:

[15:44:32.381] [Client thread/ERROR]: Unable to parse metadata from minecraft:textures/blocks/cactus_side.png
java.lang.ArrayIndexOutOfBoundsException: 7
    at chc.a(SourceFile:386) ~[17w46a.jar:?]
    at chb.a(SourceFile:154) [17w46a.jar:?]
    at chb.b(SourceFile:120) [17w46a.jar:?]
    at chb.a(SourceFile:53) [17w46a.jar:?]
    at cir.n(SourceFile:749) [17w46a.jar:?]
    at cir.a(SourceFile:187) [17w46a.jar:?]
    at cis.a(SourceFile:23) [17w46a.jar:?]
    at ry.b(SourceFile:156) [17w46a.jar:?]
    at ry.a(SourceFile:123) [17w46a.jar:?]
    at blb.al(SourceFile:484) [17w46a.jar:?]
    at blb.a(SourceFile:355) [17w46a.jar:?]
    at net.minecraft.client.main.Main.main(SourceFile:134) [17w46a.jar:?]

well if that part is fixed in latest snapshot maybe it's got to do with the other bug but, you can't prove it either way until this bug gets fixed MC-121891

Ok It no longer crashes but, the framtime appears to be alot faster at the last frame of interpolation I think there is an issue here. Observer use a timer but, the times are offsync not by much but, it's off sync compared to the rest of the frames it barley goes to the last frame then instantly goes to 0 ignoring the 30 ticks I said to wait for the next frame

Who is in charge of doing this it's pretty simple really I studied this on how to get frametime synced right

Simple code assuming vanilla has made the display frame dynamic
https://pastebin.com/MipWs1s9

Well looking at optifine and back I think the frametime was right but, let me just test custom frametime with that pastebin

yeah it appears to be right

So I think it's fixed @Georgie look and see if it's fixed then close it