Backport selected refinements from the nullability efforts in 5.0 [SPR-15656]

[spring-projects-issues]

Juergen Hoeller opened SPR-15656 and commented

The efforts around #20099 and #20276 have uncovered minor issues like missing null handling and/or missing assertions in quite a few places. Let's selectively backport some of those refinements to 4.3.x along with 5.0 GA.

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Affects: 4.3.9

Issue Links:

• Introduce null-safety of Spring Framework API [SPR-15540] #20099 Introduce null-safety of Spring Framework API
• Extend null-safety to field level [SPR-15720] #20276 Extend null-safety to field level
• SpelExpression throws NullPointerException instead of EvaluationException for primitives [SPR-16123] #20671 SpelExpression throws NullPointerException instead of EvaluationException for primitives
• setArguments(null) on MethodInvoker no longer coerces null to Object[0] [SPR-16075] #20624 setArguments(null) on MethodInvoker no longer coerces null to Object[0]

Referenced from: commits 75bd516, cc70fdc, 9fdc440