Case-insensitive boolean deserialization

[remal]

It's a fix for #1852

[cowtowncoder]

First of all, thank you for PR!

Now, as per my notes I think what is needed is support for using either "leniency" (via @JsonFormat.lenient), or case-sensitivity. Actually probably latter.
So I am not sure whether to apply this at this point.
Problem here is that there are users who want stricter handling (as well as others who want more flexible one, of course :) ), and I would like to have controls in place to allow both, before extending definition.

[remal]

@cowtowncoder I believe I saw a special Jackson setting that switches from strict/not strict. Let me do a little research on Monday...

[remal]

@cowtowncoder I thought about com.fasterxml.jackson.databind.MapperFeature.ALLOW_COERCION_OF_SCALARS. But this option is not applicable here. We can create another option, but do Jackson really need it?

[cowtowncoder]

So: since 2.10 adds more specific JsonFormat.Feature.ACCEPT_CASE_INSENSITIVE_VALUES / MapperFeature.ACCEPT_CASE_INSENSITIVE_VALUES, I think that is what needs to be used here.
Will close this PR.

[ghanekaromkar]

I tried using the new Features in my code but it does not help me against uppercased value like "TRUE"
My code
mapper.configure(MapperFeature.USE_STD_BEAN_NAMING, true) .configure(MapperFeature.ACCEPT_CASE_INSENSITIVE_VALUES, true) .configure(DeserializationFeature.ACCEPT_SINGLE_VALUE_AS_ARRAY, true) .configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false) .configure(DeserializationFeature.FAIL_ON_IGNORED_PROPERTIES, false) .configure(DeserializationFeature.FAIL_ON_NULL_FOR_PRIMITIVES, true) .configure(SerializationFeature.FAIL_ON_SELF_REFERENCES, true) .setSerializationInclusion(JsonInclude.Include.NON_EMPTY);

Maybe because BooleanDeserializer does not consider the Feature value but I could be wrong

jackson-databind/src/main/java/com/fasterxml/jackson/databind/deser/std/NumberDeserializers.java

Lines 230 to 249 in 0cb7362

	if (t == JsonToken.VALUE_STRING) {
	String text = p.getText().trim();
	// [databind#422]: Allow aliases
	if ("true".equals(text) || "True".equals(text)) {
	_verifyStringForScalarCoercion(ctxt, text);
	return Boolean.TRUE;
	}
	if ("false".equals(text) || "False".equals(text)) {
	_verifyStringForScalarCoercion(ctxt, text);
	return Boolean.FALSE;
	}
	if (text.length() == 0) {
	return (Boolean) _coerceEmptyString(ctxt, _primitive);
	}
	if (_hasTextualNull(text)) {
	return (Boolean) _coerceTextualNull(ctxt, _primitive);
	}
	return (Boolean) ctxt.handleWeirdStringValue(_valueClass, text,
	"only \"true\" or \"false\" recognized");
	}