Handle invalid XML better

[akrabat]

If the request's body contains invalid XML, don't throw an exception or
PHP warning. Instead, just return NULL from the medica parser.
This matches the way we handle JSON.

Fixes #2106

[coveralls]

Coverage decreased (-0.1%) to 97.82% when pulling 2314455 on akrabat:silent-xml-body-parser into fb5356a on slimphp:3.x.

[silentworks]

Is this not a BC break, since we are now suppressing a PHP error?

[akrabat]

I think it's a bug fix. Will go with majority opinion though.

[coveralls]

Coverage decreased (-0.1%) to 97.82% when pulling be20f3f on akrabat:silent-xml-body-parser into fb5356a on slimphp:3.x.

[codeguy]

@akrabat Forward port to 4.x too?

[akrabat]

@akrabat Forward port to 4.x too?

Yes.

[codeguy]

Do we want a test for this?

[akrabat]

Do we want a test for this?

Almost certainly :)

[codeguy]

Will merge once you get a test added.

[akrabat]

Rebased and added unit tests.

[coveralls]

Coverage increased (+0.01%) to 98.149% when pulling 7e0556c on akrabat:silent-xml-body-parser into ef36faa on slimphp:3.x.

[akrabat]

Success, @codeguy :)

[akrabat]

Can this go into 4.x too, please?