8313865: Always true condition in sun.nio.cs.CharsetMapping#readINDEXC2B #15672

naotoj · 2023-09-11T22:21:03Z

Simple clean-up for removing an unnecessary condition.

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Issue

JDK-8313865: Always true condition in sun.nio.cs.CharsetMapping#readINDEXC2B (Bug - P5)

Reviewers

Andrey Turbanov (@turbanoff - Committer)
Vyom Tewari (@vyommani - Committer)
Roger Riggs (@RogerRiggs - Reviewer)
Iris Clark (@irisclark - Reviewer)

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Update a local copy of the PR:
$ git checkout pull/15672
$ git pull https://git.openjdk.org/jdk.git pull/15672/head

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$ git pr checkout 15672

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https://git.openjdk.org/jdk/pull/15672.diff

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bridgekeeper · 2023-09-11T22:22:42Z

👋 Welcome back naoto! A progress list of the required criteria for merging this PR into master will be added to the body of your pull request. There are additional pull request commands available for use with this pull request.

openjdk · 2023-09-11T22:24:38Z

@naotoj The following label will be automatically applied to this pull request:

nio

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mlbridge · 2023-09-11T22:28:56Z

Webrevs

00: Full (eed192a2)

vyommani

Looks OK to me.

RogerRiggs

LGTM

openjdk · 2023-09-12T13:34:12Z

@naotoj This change now passes all automated pre-integration checks.

ℹ️ This project also has non-automated pre-integration requirements. Please see the file CONTRIBUTING.md for details.

After integration, the commit message for the final commit will be:

8313865: Always true condition in sun.nio.cs.CharsetMapping#readINDEXC2B

Reviewed-by: aturbanov, vtewari, rriggs, iris

You can use pull request commands such as /summary, /contributor and /issue to adjust it as needed.

At the time when this comment was updated there had been 14 new commits pushed to the master branch:

1d702d2: 8313800: AArch64: SA stack walking code having trouble finding sender frame when invoking LambdaForms is involved
e084516: 8315968: Move java.util.Digits to jdk.internal.util and refactor to reduce duplication
d75d977: 8285447: StackWalker minimal batch size should be optimized for getCallerClass
fc3e826: 8314832: Few runtime/os tests ignore vm flags
347beb2: 8315998: Remove dead ClassLoaderDataGraphKlassIteratorStatic
50158f3: 8316002: Remove unnecessary seen_dead_loader in ClassLoaderDataGraph::do_unloading
6f2684b: 8315948: JDK-8315818 broke Xcomp on libgraal
8b4f9a8: 8315990: Amend problemlisted tests to proper position
455c471: 8313277: Resolve multiple definition of 'normalize' when statically linking JDK native libraries with user code
3b422d0: 8316094: Problemlist compiler/rangechecks/TestRangeCheckHoistingScaledIV.java
... and 4 more: https://git.openjdk.org/jdk/compare/d0be73a78038faf9509623bc4ba71eb4385cd645...master

As there are no conflicts, your changes will automatically be rebased on top of these commits when integrating. If you prefer to avoid this automatic rebasing, please check the documentation for the /integrate command for further details.

➡️ To integrate this PR with the above commit message to the master branch, type /integrate in a new comment.

naotoj · 2023-09-12T18:16:10Z

Thanks all for the reviews!

/integrate

openjdk · 2023-09-12T18:19:09Z

Going to push as commit ac2dfe4.
Since your change was applied there have been 15 commits pushed to the master branch:

947dee7: 8316113: Infinite permission checking loop in java/net/spi/InetAddressResolverProvider/RuntimePermissionTest
1d702d2: 8313800: AArch64: SA stack walking code having trouble finding sender frame when invoking LambdaForms is involved
e084516: 8315968: Move java.util.Digits to jdk.internal.util and refactor to reduce duplication
d75d977: 8285447: StackWalker minimal batch size should be optimized for getCallerClass
fc3e826: 8314832: Few runtime/os tests ignore vm flags
347beb2: 8315998: Remove dead ClassLoaderDataGraphKlassIteratorStatic
50158f3: 8316002: Remove unnecessary seen_dead_loader in ClassLoaderDataGraph::do_unloading
6f2684b: 8315948: JDK-8315818 broke Xcomp on libgraal
8b4f9a8: 8315990: Amend problemlisted tests to proper position
455c471: 8313277: Resolve multiple definition of 'normalize' when statically linking JDK native libraries with user code
... and 5 more: https://git.openjdk.org/jdk/compare/d0be73a78038faf9509623bc4ba71eb4385cd645...master

Your commit was automatically rebased without conflicts.

openjdk · 2023-09-12T18:19:15Z

@naotoj Pushed as commit ac2dfe4.

💡 You may see a message that your pull request was closed with unmerged commits. This can be safely ignored.

shipilev · 2023-09-13T07:22:24Z

src/java.base/share/classes/sun/nio/cs/CharsetMapping.java

@@ -244,7 +239,7 @@ void readSINGLEBYTE() {
    void readINDEXC2B() {
        char[] map = readCharArray();
        for (int i = map.length - 1; i >= 0; i--) {
-            if (c2b == null && map[i] != -1) {
+            if (c2b == null) {


Post-review comment:

I don't quite understand this code. c2b is loop-invariant, right? So, what this does is checking for c2b != null, and if so, instantiates the c2b array with new char[map[map.length - 1] + 256]. This does not even require a loop, as written right now.

Indeed the code looks weird. Will have a deeper look. Thanks!

The code seems to read the data written with this piece of code:

jdk/make/jdk/src/classes/build/tools/charsetmapping/JIS0213.java

Line 145 in b55e418

private static void writeINDEXC2B(OutputStream out, int[] indexC2B)

but apparently it does not seem to work as expected. Since this is a very old code, not sure I would proactively modify it though.

initial commit

eed192a

openjdk bot added the rfr Pull request is ready for review label Sep 11, 2023

openjdk bot added the nio nio-dev@openjdk.org label Sep 11, 2023

turbanoff approved these changes Sep 12, 2023

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vyommani approved these changes Sep 12, 2023

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RogerRiggs approved these changes Sep 12, 2023

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openjdk bot removed ready Pull request is ready to be integrated rfr Pull request is ready for review labels Sep 12, 2023

shipilev reviewed Sep 13, 2023

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8313865: Always true condition in sun.nio.cs.CharsetMapping#readINDEXC2B #15672

8313865: Always true condition in sun.nio.cs.CharsetMapping#readINDEXC2B #15672

naotoj commented Sep 11, 2023 •

edited by openjdk bot

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openjdk bot commented Sep 12, 2023 •

edited

naotoj commented Sep 12, 2023

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openjdk bot commented Sep 12, 2023

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naotoj Sep 13, 2023

naotoj Sep 14, 2023

8313865: Always true condition in sun.nio.cs.CharsetMapping#readINDEXC2B #15672

8313865: Always true condition in sun.nio.cs.CharsetMapping#readINDEXC2B #15672

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naotoj commented Sep 11, 2023 • edited by openjdk bot

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openjdk bot commented Sep 12, 2023 • edited

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naotoj commented Sep 11, 2023 •

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