HttpHeaders.keySet() is no longer case-insensitive [SPR-15087]

[spring-projects-issues]

Andy Wilkinson opened SPR-15087 and commented

This is a regression due to #19593. Consider the following:

HttpHeaders headers = new HttpHeaders();
headers.add("X-Foo", "bar");
System.out.println(headers.keySet().contains("x-foo"));

With M3 it outputs true. With M4 it outputs false.

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Affects: 5.0 M4

Issue Links:

• LinkedCaseInsensitiveMap does not properly support Java 8's merge() and compute() methods [SPR-15026] #19593 LinkedCaseInsensitiveMap does not properly support Java 8's merge() and compute() methods

[spring-projects-issues]

Juergen Hoeller commented

Any specific reason why you're calling keySet().contains instead of simply containsKey there? It's a regression in any case, just wondering...

[spring-projects-issues]

Andy Wilkinson commented

There's some separation between the code that's dealing with HttpHeaders and the code that checks to see if a particular header exists. The latter code is passed a Set of the header names so it can't use containsKey.

[spring-projects-issues]

Juergen Hoeller commented

We're overriding containsKey on our internal LinkedHashMap now, implicitly picked up by its keySet() implementation.

[spring-projects-issues]

Christoph Dreis commented

Hey. Was just wondering, if this will be backported to 4.3.x? Considering #19593 has also the fix version of 4.3.6