Replace runtime panics with the matching Java exceptions by dlunch · Pull Request #174 · dlunch/RustJava

dlunch · 2026-07-16T05:20:21Z

Summary

An audit of every unwrap() in the runtime found panics reachable from ordinary Java code — starting from File.length() crashing on a file that simply doesn't exist. Each is replaced with the exception (or return value) the JDK produces; expected outputs for all new fixtures are generated by running them on a real JVM.

Fixes

File / streams

File.length() returns 0 for a missing file (spec) instead of panicking; isDirectory/isFile drop their guard-then-unwrap shape.
FileImpl in the native runtime panicked on any failing open, so the existing FileNotFoundException guards in FileInputStream/RandomAccessFile were unreachable. It now maps open/read/write/seek failures to IOError (new Io variant), FileOutputStream gains the same guard, and all file I/O operations (read, write, seek, available, length, setLength, getFilePointer) throw java.io.IOException on failure via a shared helper.

Class.forName

Panicked for any class not already loaded (it only consulted the registry). It now resolves (loads) the class and throws ClassNotFoundException (new runtime class, extends Exception per the 1.2 hierarchy) when resolution fails.

Unpaired surrogates

StringBuffer.append(char) / append(char[],int,int) panicked on an unpaired surrogate. The internal append is now UTF-16-based, so building a surrogate pair char by char produces the correct string; String.valueOf(char) constructs through [C for the same reason; PrintStream.println(char) replaces an unpaired surrogate with ? matching the JDK charset encoder.

Zip

new ZipFile(...) on a non-zip file panicked in ZipArchive::new. The constructor now validates the archive (matching the JDK's timing) and throws java.util.zip.ZipException (new runtime class, extends IOException); getInputStream returns null for an entry not in the archive.

Not converted (audited, intentionally left)

Interpreter stack pops, thread-attach lookups, guarded unwraps — invariants.
Uncaught-exception stack-trace printing in Thread — error path of the error path, inside a spawn closure.
GregorianCalendar on out-of-range fields — the correct behavior is lenient normalization (a feature), not an exception.
ClassInfo::parse on a malformed classfile — needs ClassFormatError plumbing through jvm-less sync code (existing TODO).

Test plan

E2E fixtures with real-JVM-generated expected output, each verified to fail before its fix: FileLength (missing-file length/exists), FileErrors (FileNotFoundException from FileInputStream/FileOutputStream/RandomAccessFile), ForName (loads java.util.Vector, ClassNotFoundException for an unknown name), SurrogateChars (pair building, lone-surrogate length/println), ZipCorrupt (ZipException from the constructor). cargo test --workspace green, fmt clean, clippy no new warnings.

An unwrap audit found panics reachable from ordinary Java code: - File.length() returns 0 for a missing file; isDirectory/isFile lose their guard-then-unwrap shape - FileImpl (native runtime) maps open/read/write/seek failures to IOError instead of panicking, so FileInputStream and RandomAccessFile guards actually produce FileNotFoundException; FileOutputStream gains the same guard - File I/O operations (read/write/seek/available/length/setLength) throw java.io.IOException on failure via a shared helper - Class.forName resolves the class and throws ClassNotFoundException (new runtime class) instead of panicking on any not-yet-loaded name - StringBuffer.append(char)/append(char[]) keep exact UTF-16 units so unpaired surrogates no longer panic and pairs built char by char survive; String.valueOf(char) builds through [C for the same reason - PrintStream.println(char) replaces an unpaired surrogate with '?' like the JDK charset encoder - ZipFile validates the archive in its constructor and throws java.util.zip.ZipException (new runtime class) for a malformed archive; getInputStream returns null for a missing entry Expected outputs for the new fixtures are generated by a real JVM. Remaining unwraps are invariants (interpreter stack discipline, thread attach), guarded lookups, or documented gaps (lenient calendar normalization, ClassFormatError plumbing).

codecov · 2026-07-16T05:21:15Z

Codecov Report

❌ Patch coverage is 66.94215% with 40 lines in your changes missing coverage. Please review.
✅ Project coverage is 83.89%. Comparing base (62cf0c6) to head (760e734).
⚠️ Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
..._runtime/src/classes/java/io/random_access_file.rs	5.88%	16 Missing ⚠️
..._runtime/src/classes/java/io/file_output_stream.rs	50.00%	6 Missing ⚠️
...src/classes/java/lang/class_not_found_exception.rs	80.00%	5 Missing ⚠️
...runtime/src/classes/java/util/zip/zip_exception.rs	80.00%	5 Missing ⚠️
...a_runtime/src/classes/java/io/file_input_stream.rs	50.00%	4 Missing ⚠️
java_runtime/src/classes/java/io/file.rs	33.33%	2 Missing ⚠️
java_runtime/src/classes/java/util/zip/zip_file.rs	83.33%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #174      +/-   ##
==========================================
+ Coverage   83.71%   83.89%   +0.18%     
==========================================
  Files         171      173       +2     
  Lines       12867    12939      +72     
==========================================
+ Hits        10771    10855      +84     
+ Misses       2096     2084      -12

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Pull request overview

This PR hardens the RustJava runtime by removing panic paths reachable from ordinary Java code and mapping failures to the Java exceptions/behaviors that the JDK produces, with new E2E fixtures whose expected outputs were generated from a reference JVM.

Changes:

Replace unwrap()-based runtime panics in file I/O, class loading, surrogate handling, and zip handling with JDK-aligned exceptions/return values.
Add runtime classes java.lang.ClassNotFoundException and java.util.zip.ZipException and wire them into the runtime loader.
Add new Java fixtures and golden outputs covering missing files, I/O errors, Class.forName, surrogate chars, and corrupt zip behavior.

Reviewed changes

Copilot reviewed 28 out of 33 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
test_data/ZipCorrupt.txt	Golden output for corrupt/non-zip `ZipFile` constructor behavior.
test_data/SurrogateChars.txt	Golden output for surrogate-pair and lone-surrogate behaviors.
test_data/src/ZipCorrupt.java	Fixture exercising `ZipFile` constructor throwing `ZipException`.
test_data/src/SurrogateChars.java	Fixture exercising surrogate pair construction and lone surrogate printing.
test_data/src/ForName.java	Fixture exercising `Class.forName` success + `ClassNotFoundException`.
test_data/src/FileLength.java	Fixture for `File.exists()` + `File.length()` on missing file.
test_data/src/FileErrors.java	Fixture for `FileNotFoundException` from common file I/O constructors.
test_data/ForName.txt	Golden output for `Class.forName` fixture.
test_data/FileLength.txt	Golden output for missing-file `File.length()` returning `0`.
test_data/FileErrors.txt	Golden output for missing-file/dir constructor failures.
src/runtime/io.rs	Replace several I/O `unwrap()`s with `IOError` propagation in the native runtime file impls.
src/runtime.rs	Change runtime `open()` to return an `IOError` instead of panicking on open failure.
java_runtime/src/runtime/io.rs	Add `IOError::Io` variant for non-NotFound I/O failures.
java_runtime/src/loader.rs	Register new runtime classes (`ClassNotFoundException`, `ZipException`).
java_runtime/src/classes/java/util/zip/zip_file.rs	Convert zip parsing/entry access panics into `ZipException` and JDK-like null returns.
java_runtime/src/classes/java/util/zip/zip_exception.rs	Add `java.util.zip.ZipException` runtime class (extends `IOException`).
java_runtime/src/classes/java/util/zip.rs	Export `ZipException` module/type from `java.util.zip`.
java_runtime/src/classes/java/lang/string.rs	Preserve unpaired surrogates in `String.valueOf(char)` by constructing via `[C`.
java_runtime/src/classes/java/lang/string_buffer.rs	Switch internal appends to UTF-16-based append to preserve unpaired surrogates.
java_runtime/src/classes/java/lang/class.rs	Make `Class.forName` resolve/load and throw `ClassNotFoundException` instead of panicking.
java_runtime/src/classes/java/lang/class_not_found_exception.rs	Add `java.lang.ClassNotFoundException` runtime class (extends `Exception`).
java_runtime/src/classes/java/lang.rs	Export `ClassNotFoundException` from `java.lang` module.
java_runtime/src/classes/java/io/random_access_file.rs	Route file op failures through shared `checked()` helper instead of `unwrap()`.
java_runtime/src/classes/java/io/print_stream.rs	Avoid panicking on surrogate `char` printing; replace with `?`.
java_runtime/src/classes/java/io/input_stream_reader.rs	Propagate array-buffer read failures instead of unwrapping.
java_runtime/src/classes/java/io/file.rs	Make `File.isDirectory/isFile/length` avoid unwraps and match JDK missing-file behavior.
java_runtime/src/classes/java/io/file_output_stream.rs	Add open guard for `FileOutputStream` and propagate write failures as `IOException`.
java_runtime/src/classes/java/io/file_input_stream.rs	Propagate read/available failures as `IOException` via `checked()`.
java_runtime/src/classes/java/io.rs	Add shared `checked()` helper to convert runtime I/O failures into `java.io.IOException`.

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chatgpt-codex-connector · 2026-07-16T05:25:14Z

-        Ok(class.into())
+        match jvm.resolve_class(&qualified_name).await {
+            Ok(class) => Ok(class.java_class().into()),
+            Err(_) => Err(jvm.exception("java/lang/ClassNotFoundException", &rust_name).await),


Preserve linkage errors from Class.forName

When the requested class file is present but resolving one of its superclasses or interfaces fails, resolve_class propagates that Java error (for example NoClassDefFoundError from jvm/src/jvm.rs when a dependency is missing). This blanket Err(_) converts those linkage failures into ClassNotFoundException, so Java code can incorrectly catch them as CNFE instead of seeing the linkage error that Class.forName should propagate. Only the actual “requested class not found” case should be remapped here; other resolve_class errors should be returned unchanged.

Useful? React with 👍 / 👎.

Judged the two remaining remote branches on the fork: - dependabot/cargo/tracing-attributes-0.1.31: deleted. PR #4 (fa92ef9) removed the tracing-attributes direct dependency outright, so the branch patches a Cargo.toml line that no longer exists. - wie-ktf-hardening: preserved. 8 of its 12 commits are already in upstream/main via squash merges (dlunch#174 dlunch#175 dlunch#176 dlunch#177 dlunch#180 dlunch#182); git cherry missed this because origin/main trails upstream/main by 20 commits. 4 commits carry residual value. No code changes. Co-authored-by: jun0 <junyoung.choi.a@miraeasset.com> Co-authored-by: Claude <noreply@anthropic.com>

…am-sync-s1-tracing-cut-1f356ae] * Bump bytemuck from 1.25.0 to 1.25.1 (dlunch#173) Bumps [bytemuck](https://github.com/Lokathor/bytemuck) from 1.25.0 to 1.25.1. - [Changelog](https://github.com/Lokathor/bytemuck/blob/main/changelog.md) - [Commits](Lokathor/bytemuck@v1.25.0...v1.25.1) --- updated-dependencies: - dependency-name: bytemuck dependency-version: 1.25.1 dependency-type: direct:production update-type: version-update:semver-patch ... Signed-off-by: dependabot[bot] <support@github.com> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com> * Replace runtime panics with the matching Java exceptions (dlunch#174) * Replace runtime panics with the matching Java exceptions An unwrap audit found panics reachable from ordinary Java code: - File.length() returns 0 for a missing file; isDirectory/isFile lose their guard-then-unwrap shape - FileImpl (native runtime) maps open/read/write/seek failures to IOError instead of panicking, so FileInputStream and RandomAccessFile guards actually produce FileNotFoundException; FileOutputStream gains the same guard - File I/O operations (read/write/seek/available/length/setLength) throw java.io.IOException on failure via a shared helper - Class.forName resolves the class and throws ClassNotFoundException (new runtime class) instead of panicking on any not-yet-loaded name - StringBuffer.append(char)/append(char[]) keep exact UTF-16 units so unpaired surrogates no longer panic and pairs built char by char survive; String.valueOf(char) builds through [C for the same reason - PrintStream.println(char) replaces an unpaired surrogate with '?' like the JDK charset encoder - ZipFile validates the archive in its constructor and throws java.util.zip.ZipException (new runtime class) for a malformed archive; getInputStream returns null for a missing entry Expected outputs for the new fixtures are generated by a real JVM. Remaining unwraps are invariants (interpreter stack discipline, thread attach), guarded lookups, or documented gaps (lenient calendar normalization, ClassFormatError plumbing). * Inline the IOException conversion at each I/O call site * Return the same Thread object from Thread.currentThread() (dlunch#175) Every attached thread now owns its java/lang/Thread instance: attach takes the instance for threads started via Thread.start (so currentThread() inside run() is the started Thread object) and creates one otherwise (bootstrap, external attachers). currentThread() returns the stored instance, and the GC roots it per thread. Also parse unrecognized classfile attributes as an opaque Unknown variant instead of failing — JVMS 4.7.1 requires silently ignoring them, and the anonymous-class fixture carries EnclosingMethod and Signature attributes the parser rejected. Expected output for the fixture is generated by a real JVM. * Add Java primitive wrapper classes (dlunch#176) * Add Java primitive wrapper classes * Use Character digit semantics for numeric parsing * Bump tokio from 1.52.3 to 1.52.4 (dlunch#179) Bumps [tokio](https://github.com/tokio-rs/tokio) from 1.52.3 to 1.52.4. - [Release notes](https://github.com/tokio-rs/tokio/releases) - [Commits](tokio-rs/tokio@tokio-1.52.3...tokio-1.52.4) --- updated-dependencies: - dependency-name: tokio dependency-version: 1.52.4 dependency-type: direct:production update-type: version-update:semver-patch ... Signed-off-by: dependabot[bot] <support@github.com> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com> * [rustjava-upstream-sync-s1-tracing-cut-1f356ae] docs: record S1 landing (conflicts 2, setProperty descriptor breakage) --------- Signed-off-by: dependabot[bot] <support@github.com> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com> Co-authored-by: Inseok Lee <git@dlun.ch> Co-authored-by: jun0 <junyoung.choi.a@miraeasset.com>

…am-sync-s2] * Bump bytemuck from 1.25.0 to 1.25.1 (dlunch#173) Bumps [bytemuck](https://github.com/Lokathor/bytemuck) from 1.25.0 to 1.25.1. - [Changelog](https://github.com/Lokathor/bytemuck/blob/main/changelog.md) - [Commits](Lokathor/bytemuck@v1.25.0...v1.25.1) --- updated-dependencies: - dependency-name: bytemuck dependency-version: 1.25.1 dependency-type: direct:production update-type: version-update:semver-patch ... Signed-off-by: dependabot[bot] <support@github.com> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com> * Replace runtime panics with the matching Java exceptions (dlunch#174) * Replace runtime panics with the matching Java exceptions An unwrap audit found panics reachable from ordinary Java code: - File.length() returns 0 for a missing file; isDirectory/isFile lose their guard-then-unwrap shape - FileImpl (native runtime) maps open/read/write/seek failures to IOError instead of panicking, so FileInputStream and RandomAccessFile guards actually produce FileNotFoundException; FileOutputStream gains the same guard - File I/O operations (read/write/seek/available/length/setLength) throw java.io.IOException on failure via a shared helper - Class.forName resolves the class and throws ClassNotFoundException (new runtime class) instead of panicking on any not-yet-loaded name - StringBuffer.append(char)/append(char[]) keep exact UTF-16 units so unpaired surrogates no longer panic and pairs built char by char survive; String.valueOf(char) builds through [C for the same reason - PrintStream.println(char) replaces an unpaired surrogate with '?' like the JDK charset encoder - ZipFile validates the archive in its constructor and throws java.util.zip.ZipException (new runtime class) for a malformed archive; getInputStream returns null for a missing entry Expected outputs for the new fixtures are generated by a real JVM. Remaining unwraps are invariants (interpreter stack discipline, thread attach), guarded lookups, or documented gaps (lenient calendar normalization, ClassFormatError plumbing). * Inline the IOException conversion at each I/O call site * Return the same Thread object from Thread.currentThread() (dlunch#175) Every attached thread now owns its java/lang/Thread instance: attach takes the instance for threads started via Thread.start (so currentThread() inside run() is the started Thread object) and creates one otherwise (bootstrap, external attachers). currentThread() returns the stored instance, and the GC roots it per thread. Also parse unrecognized classfile attributes as an opaque Unknown variant instead of failing — JVMS 4.7.1 requires silently ignoring them, and the anonymous-class fixture carries EnclosingMethod and Signature attributes the parser rejected. Expected output for the fixture is generated by a real JVM. * Add Java primitive wrapper classes (dlunch#176) * Add Java primitive wrapper classes * Use Character digit semantics for numeric parsing * Bump tokio from 1.52.3 to 1.52.4 (dlunch#179) Bumps [tokio](https://github.com/tokio-rs/tokio) from 1.52.3 to 1.52.4. - [Release notes](https://github.com/tokio-rs/tokio/releases) - [Commits](tokio-rs/tokio@tokio-1.52.3...tokio-1.52.4) --- updated-dependencies: - dependency-name: tokio dependency-version: 1.52.4 dependency-type: direct:production update-type: version-update:semver-patch ... Signed-off-by: dependabot[bot] <support@github.com> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com> * Add CLDC 1.1 core API compatibility (dlunch#177) * Add CLDC 1.1 core API compatibility * Fix CI lint and improve CLDC coverage * Fix array assignability and reader progress * [rustjava-upstream-sync-s2] docs: record S2 landing (cut af4f6f8, conflicts 5, ancestry restore) --------- Signed-off-by: dependabot[bot] <support@github.com> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com> Co-authored-by: Inseok Lee <git@dlun.ch> Co-authored-by: jun0 <junyoung.choi.a@miraeasset.com>

…m-sync-s3] * Bump bytemuck from 1.25.0 to 1.25.1 (dlunch#173) Bumps [bytemuck](https://github.com/Lokathor/bytemuck) from 1.25.0 to 1.25.1. - [Changelog](https://github.com/Lokathor/bytemuck/blob/main/changelog.md) - [Commits](Lokathor/bytemuck@v1.25.0...v1.25.1) --- updated-dependencies: - dependency-name: bytemuck dependency-version: 1.25.1 dependency-type: direct:production update-type: version-update:semver-patch ... Signed-off-by: dependabot[bot] <support@github.com> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com> * Replace runtime panics with the matching Java exceptions (dlunch#174) * Replace runtime panics with the matching Java exceptions An unwrap audit found panics reachable from ordinary Java code: - File.length() returns 0 for a missing file; isDirectory/isFile lose their guard-then-unwrap shape - FileImpl (native runtime) maps open/read/write/seek failures to IOError instead of panicking, so FileInputStream and RandomAccessFile guards actually produce FileNotFoundException; FileOutputStream gains the same guard - File I/O operations (read/write/seek/available/length/setLength) throw java.io.IOException on failure via a shared helper - Class.forName resolves the class and throws ClassNotFoundException (new runtime class) instead of panicking on any not-yet-loaded name - StringBuffer.append(char)/append(char[]) keep exact UTF-16 units so unpaired surrogates no longer panic and pairs built char by char survive; String.valueOf(char) builds through [C for the same reason - PrintStream.println(char) replaces an unpaired surrogate with '?' like the JDK charset encoder - ZipFile validates the archive in its constructor and throws java.util.zip.ZipException (new runtime class) for a malformed archive; getInputStream returns null for a missing entry Expected outputs for the new fixtures are generated by a real JVM. Remaining unwraps are invariants (interpreter stack discipline, thread attach), guarded lookups, or documented gaps (lenient calendar normalization, ClassFormatError plumbing). * Inline the IOException conversion at each I/O call site * Return the same Thread object from Thread.currentThread() (dlunch#175) Every attached thread now owns its java/lang/Thread instance: attach takes the instance for threads started via Thread.start (so currentThread() inside run() is the started Thread object) and creates one otherwise (bootstrap, external attachers). currentThread() returns the stored instance, and the GC roots it per thread. Also parse unrecognized classfile attributes as an opaque Unknown variant instead of failing — JVMS 4.7.1 requires silently ignoring them, and the anonymous-class fixture carries EnclosingMethod and Signature attributes the parser rejected. Expected output for the fixture is generated by a real JVM. * Add Java primitive wrapper classes (dlunch#176) * Add Java primitive wrapper classes * Use Character digit semantics for numeric parsing * Bump tokio from 1.52.3 to 1.52.4 (dlunch#179) Bumps [tokio](https://github.com/tokio-rs/tokio) from 1.52.3 to 1.52.4. - [Release notes](https://github.com/tokio-rs/tokio/releases) - [Commits](tokio-rs/tokio@tokio-1.52.3...tokio-1.52.4) --- updated-dependencies: - dependency-name: tokio dependency-version: 1.52.4 dependency-type: direct:production update-type: version-update:semver-patch ... Signed-off-by: dependabot[bot] <support@github.com> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com> * Add CLDC 1.1 core API compatibility (dlunch#177) * Add CLDC 1.1 core API compatibility * Fix CI lint and improve CLDC coverage * Fix array assignability and reader progress * Harden JVM runtime correctness (dlunch#180) * Harden JVM runtime correctness * Address classfile review findings * Move class initialization tests to Java fixture * Separate classfile validation from JVM verification * Remove ClassFileError re-export * [rustjava-upstream-sync-s2] docs: record S2 landing (cut af4f6f8, conflicts 5, ancestry restore) * [rustjava-upstream-sync-s3] docs: record S3 landing (cut 822504b, conflicts 11) + refresh STATE 「다음」 STATE.md ③-0 pointed at rustjava-pr8-claude-md-prune-disposition as top priority on the grounds that its review.md was missing and gate 2 had stalled. Both are false now: PR #8 is MERGED (2026-08-18T19:26:08Z -> 00bddf3) and the review reports exist. Item closed, list renumbered, ⑤ operating notes re-measured (open PRs 2 -> 1, dead branch row dropped). * [rustjava-upstream-sync-s3] docs: record S2 landing (11ef501) and correct the ancestry-axis prediction --------- Signed-off-by: dependabot[bot] <support@github.com> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com> Co-authored-by: Inseok Lee <git@dlun.ch> Co-authored-by: jun0 <junyoung.choi.a@miraeasset.com>

* Bump bytemuck from 1.25.0 to 1.25.1 (dlunch#173) Bumps [bytemuck](https://github.com/Lokathor/bytemuck) from 1.25.0 to 1.25.1. - [Changelog](https://github.com/Lokathor/bytemuck/blob/main/changelog.md) - [Commits](Lokathor/bytemuck@v1.25.0...v1.25.1) --- updated-dependencies: - dependency-name: bytemuck dependency-version: 1.25.1 dependency-type: direct:production update-type: version-update:semver-patch ... Signed-off-by: dependabot[bot] <support@github.com> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com> * Replace runtime panics with the matching Java exceptions (dlunch#174) * Replace runtime panics with the matching Java exceptions An unwrap audit found panics reachable from ordinary Java code: - File.length() returns 0 for a missing file; isDirectory/isFile lose their guard-then-unwrap shape - FileImpl (native runtime) maps open/read/write/seek failures to IOError instead of panicking, so FileInputStream and RandomAccessFile guards actually produce FileNotFoundException; FileOutputStream gains the same guard - File I/O operations (read/write/seek/available/length/setLength) throw java.io.IOException on failure via a shared helper - Class.forName resolves the class and throws ClassNotFoundException (new runtime class) instead of panicking on any not-yet-loaded name - StringBuffer.append(char)/append(char[]) keep exact UTF-16 units so unpaired surrogates no longer panic and pairs built char by char survive; String.valueOf(char) builds through [C for the same reason - PrintStream.println(char) replaces an unpaired surrogate with '?' like the JDK charset encoder - ZipFile validates the archive in its constructor and throws java.util.zip.ZipException (new runtime class) for a malformed archive; getInputStream returns null for a missing entry Expected outputs for the new fixtures are generated by a real JVM. Remaining unwraps are invariants (interpreter stack discipline, thread attach), guarded lookups, or documented gaps (lenient calendar normalization, ClassFormatError plumbing). * Inline the IOException conversion at each I/O call site * Return the same Thread object from Thread.currentThread() (dlunch#175) Every attached thread now owns its java/lang/Thread instance: attach takes the instance for threads started via Thread.start (so currentThread() inside run() is the started Thread object) and creates one otherwise (bootstrap, external attachers). currentThread() returns the stored instance, and the GC roots it per thread. Also parse unrecognized classfile attributes as an opaque Unknown variant instead of failing — JVMS 4.7.1 requires silently ignoring them, and the anonymous-class fixture carries EnclosingMethod and Signature attributes the parser rejected. Expected output for the fixture is generated by a real JVM. * Add Java primitive wrapper classes (dlunch#176) * Add Java primitive wrapper classes * Use Character digit semantics for numeric parsing * Bump tokio from 1.52.3 to 1.52.4 (dlunch#179) Bumps [tokio](https://github.com/tokio-rs/tokio) from 1.52.3 to 1.52.4. - [Release notes](https://github.com/tokio-rs/tokio/releases) - [Commits](tokio-rs/tokio@tokio-1.52.3...tokio-1.52.4) --- updated-dependencies: - dependency-name: tokio dependency-version: 1.52.4 dependency-type: direct:production update-type: version-update:semver-patch ... Signed-off-by: dependabot[bot] <support@github.com> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com> * Add CLDC 1.1 core API compatibility (dlunch#177) * Add CLDC 1.1 core API compatibility * Fix CI lint and improve CLDC coverage * Fix array assignability and reader progress * Harden JVM runtime correctness (dlunch#180) * Harden JVM runtime correctness * Address classfile review findings * Move class initialization tests to Java fixture * Separate classfile validation from JVM verification * Remove ClassFileError re-export * Bump tokio from 1.52.4 to 1.53.0 (dlunch#181) Bumps [tokio](https://github.com/tokio-rs/tokio) from 1.52.4 to 1.53.0. - [Release notes](https://github.com/tokio-rs/tokio/releases) - [Commits](tokio-rs/tokio@tokio-1.52.4...tokio-1.53.0) --- updated-dependencies: - dependency-name: tokio dependency-version: 1.53.0 dependency-type: direct:production update-type: version-update:semver-minor ... Signed-off-by: dependabot[bot] <support@github.com> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com> * Hide classfile errors behind class definition errors * Delegate null-parent class loading to bootstrap * Remove duplicate array instance methods * Add JNI-style global references (dlunch#182) * Generalize monitor instance arguments * Add CDC text formatting APIs (dlunch#183) * Add CDC text formatting APIs * Add integer number format factories * Fix text format position handling * Add CLI classpath options (dlunch#184) * Add CLI classpath options * Simplify URL classpath lookup * Fix platform classpath handling * Use File path separator for class loading * Separate RustJar class loading * [rustjava-upstream-sync-s4] test: widen test_timer_periodic margin 500ms->2000ms (upstream 3296139 slowed TimerThread) * [rustjava-upstream-sync-s4] docs: record S4 landing (cut 3296139, conflicts 20->2) + S3 landing sha * [rustjava-upstream-sync-s4] docs: correct the timer finding - chronic boundary test, not a cut regression The prior wording compared a standalone run on origin/main against parallel full-suite runs on upstream and called the gap a regression. Matched-condition alternating runs show no difference (standalone x10: pre 3.5 mean / post 3.5 mean; full-suite x8: no difference). Upstream widened this same margin in 895d67d (2025-08) and ad8b477 (2025-10), both already ancestors of main, 11 months before e557673 (2026-07) which the prior wording blamed. sleep 2000 and both conflict resolutions are untouched. Comment-only in .rs; no code change. * [rustjava-upstream-sync-s4] docs: retarget follow-up (4) - no timer perf regression exists; the open axis is our test's wall-clock dependence REPORT.md line 27 already said the 'imported upstream regression' framing was wrong, but the follow-up list 20 lines below still carried it verbatim - and that list is what the next round tickets from. Retargeted to the axis that does exist (our test design, no upstream sending). --------- Signed-off-by: dependabot[bot] <support@github.com> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com> Co-authored-by: Inseok Lee <git@dlun.ch> Co-authored-by: jun0 <junyoung.choi.a@miraeasset.com>

Copilot AI review requested due to automatic review settings July 16, 2026 05:20

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Inline the IOException conversion at each I/O call site

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dlunch merged commit fe5d116 into main Jul 16, 2026
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dlunch deleted the fix-normal-path-panics branch July 16, 2026 05:24

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Jun025 mentioned this pull request Jul 25, 2026

[2026-07-25-rustjava-branch-hygiene] docs: record remote branch hygiene verdicts Jun025/RustJava#6

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Replace runtime panics with the matching Java exceptions - #174

Replace runtime panics with the matching Java exceptions#174
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dlunch commented Jul 16, 2026

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