RFR: 8283041: [javadoc] Crashes using {@return} with @param

[Pavel Rappo]

On Fri, 11 Mar 2022 15:53:34 GMT, Jonathan Gibbons <jjg at openjdk.org> wrote:

>> The inline `{@return}` tag is relatively new and will require developers to change their habits. According to the [specification](https://docs.oracle.com/en/java/javase/17/docs/specs/javadoc/doc-comment-spec.html#return), the inline version of `@return` "may only occur at the beginning of a method's description".
>> 
>> When used like in the description of the issue, the tag technically belongs to the block `@param` tag and not to the body of the doc comment, which one might think is the case. Thus, the "full body" (let alone "first sentence") collection of doc nodes is empty. Hence, IndexOutOfBoundsException when trying to access its first element. 
>> 
>> Since we don't have a method that returns the **complete** doc comment (yes, "getFullBody" is a bit of a misleading name), whose first element we could check against `{@return}`, I check `isEmpty()` before accessing the first element.
>> 
>> Interestingly, `{@summary}` (must also appear first) lint is performed differently. However, I decided not to copy it since it operates on a lower level of abstraction: characters and strings thereof.
>
> src/jdk.javadoc/share/classes/jdk/javadoc/internal/doclint/Checker.java line 988:
> 
>> 986:         if (tree.isInline()) {
>> 987:             DocCommentTree dct = getCurrentPath().getDocComment();
>> 988:             if (dct.getFullBody().isEmpty() || tree != dct.getFullBody().get(0)) {
> 
> It should not be necessary to resort to `getFullBody`.  It should be enough to check the first sentence, but that check should not throw an exception.

I thought that getting the first sentence would unnecessarily trigger sentence segmentation and read less clearly. But I can revert it if you like.

-------------

PR: https://git.openjdk.java.net/jdk/pull/7788