RFR: 8361613: System.console() should only be available for interactive terminal [v2]

[Justin Lu]

On Fri, 11 Jul 2025 22:07:01 GMT, Naoto Sato <naoto at openjdk.org> wrote:

>> In prior JDK releases, `System.console()` could return a `Console` instance even when the JVM was not attached to an interactive terminal. This could lead to confusion, particularly when input was not from a keyboard or output was redirected, such as to or from a file or pipe, especially when using methods like `readPassword()`. Starting with JDK 25, the default behavior has changed: `System.console()` now returns `null` if standard input and/or output is redirected. However, if a JLine-based Console implementation is explicitly specified via the system property `-Djdk.console=jdk.internal.le`, the previous behavior may still occur.
>> This PR aims to align the behavior of the JLine-based `Console` implementation with the default `System.console()` behavior. The actual code change is a one-liner in `JdkConsoleProviderImpl.java`; the rest of the changes are adjustments to test cases to reflect the updated behavior. A corresponding CSR has also been drafted.
>
> Naoto Sato has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Update test/jdk/java/io/Console/LocaleTest.java
>   
>   Co-authored-by: Andrey Turbanov <turbanoff at gmail.com>

test/jdk/java/io/Console/DefaultCharsetTest.java line 52:

> 50:     void testDefaultCharset(String stdoutEncoding) throws Exception {
> 51:         // check "expect" command availability
> 52:         var expect = Paths.get("/usr/bin/expect");

We only need to check "expect" availability once, so we should move this check to a `@BeforeAll` static method. It's also more clear that this check is a precondition, and not part of the actual test. Applies to the other locations, but primarily the other parameterized tests.

test/jdk/java/io/Console/ModuleSelectionTest.java line 32:

> 30:  * @library /test/lib
> 31:  * @build jdk.test.lib.Utils
> 32:  *        jdk.test.lib.JDKToolFinder

Is `jdk.test.lib.JDKToolFinder` needed?

test/jdk/java/io/Console/ModuleSelectionTest.java line 65:

> 63:     @ParameterizedTest
> 64:     @MethodSource("options")
> 65:     void testWithoutExpect(String opts, String expected) throws Exception {

`expected` param looks unused.

test/jdk/java/io/Console/ModuleSelectionTest.java line 75:

> 73:     @ParameterizedTest
> 74:     @MethodSource("options")
> 75:     void testWithExpect(String opts, String expected) throws Exception {

I think it would be more clear if these tests were renamed to `expectConsoleTest` and `noConsoleTest` or something along those lines.

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PR Review Comment: https://git.openjdk.org/jdk/pull/26273#discussion_r2205500449
PR Review Comment: https://git.openjdk.org/jdk/pull/26273#discussion_r2205576522
PR Review Comment: https://git.openjdk.org/jdk/pull/26273#discussion_r2205557781
PR Review Comment: https://git.openjdk.org/jdk/pull/26273#discussion_r2205573038