Non-locale aware encoding of doubles, closes #1041

[Grundik]

Q	A
Bug fix?	yes
New feature?	no
Doc updated	no
BC breaks?	no
Deprecations?	no
Tests pass?	yes
Fixed tickets	#1041
License	MIT

[goetas]

Thanks for this PR.

not sure if JSON encode is the best tool for the job here.

has anybody a better idea?

@Grundik can you crate a test case for this?

[Grundik]

I've added tests. Strictly speaking, existing tests already failing on systems with inconvenient system locale. Its only a matter of default locale.

json_encode exports float value as string in machine-readable form without losing precision. Its the simplest way of accomplishment of such task. Another way could be switching to C locale, but that could cause severe performance degradation.

[goetas]

What about this https://3v4l.org/WgoZh ? (does not require json)

[Grundik]

Thats better, and does not requires integer hack. I've made changes to PR.

But: var_exports works good on floats only on PHP >= 7.0.2, so backporting this bugfix to older versions should be done via json_encode, if that would be done.

[goetas]

This package requires php ^7.2 so it should not be a problem

[Grundik]

We encountered this bug in 5.6, and we have so stick to this version for now, so I have backported this fix to 1.13.0 (https://github.com/Grundik/serializer/commits/bugfix-1041-1.13.0 if you're interested).

[goetas]

Thanks!