eq has problems operating on range's index since 0.13

[yacoob]

Create a new site, set theme, create three posts.
Add this simple template at section/post.html:

{{ $count := sub (len .Data.Pages) 1 }}
<h1>$count = {{ $count  }}</h1>
{{ range $index, $value := .Data.Pages }}
index = {{ $index }} and
(index == $count) is {{ eq $index $count }}<br>
{{ end }}

With hugo 0.12 I get this expected output:

$count = 2

index = 0 and (index == $count) is false
index = 1 and (index == $count) is false
index = 2 and (index == $count) is true

With hugo 0.13 and beyond, I get this unexpected output:

$count = 2

index = 0 and (index == $count) is false
index = 1 and (index == $count) is false
index = 2 and (index == $count) is false

Same thing happens if I replace $count in comparison with a fixed number. There seem to be something wrong with $index itself and the way eq uses it :(

[bep]

The implementation of Eq hasn't changed (reflect.DeepEqual(x, y)) and range is also a Go construct, so something in Go must have created this.

[bep]

OK, I see what happened:

The signature of sub changed from int to int64.

@tatsushid may have some insight.

[tatsushid]

OK, I'll check it tonight.

[tatsushid]

As you mentioned, it's related to changing math functions return types. I'll send PR

[yacoob]

Thanks for a quick fix!

[sebz]

Hi guys, I've just switch to 0.13 and I am also impacted.
Is there a workaround or should I wait for 0.14 to get the fix...? If it is the latter, when do you plan to release it?

Thanks :)

[bep]

@sebz there was a workaround posted on the discuss forum a while ago. Cannot remember what, but believe it was to do a dummy operation on the result of sub to convert it into an int ...

[sebz]

In fact I get the error with mod instead of sub, I was assuming that it was the same issue.
Anyway, I'll search on the forum and make some tests.

Thanks @bep !

[sebz]

Did not find it on the forum (just found a thread where you point toward this issue).
But doing the dummy operation trick ( adding 0 to the mod result) does the job for me!

Thanks again 👍

[bep]

@sebz Good -- in your case you could also use modBool, which does not suffer from this issue.

[sebz]

OK, thanks for the tip.

[github-actions]

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