Patch OpenJDK¶

All patches applied to OpenJDK should follow the naming convention:

Upstream patches: jdk-<bug-number>[-proposed].diff. Use -proposed suffix for patches that are not yet applied in the upstream repository, e.g. not backported yet.
Debian and Ubuntu-specific patches: <name>.diff

All new patches should have DEP-3 headers.

Ensure that every patch that updates the upstream source tree is submitted upstream.

OpenJDK developer guide¶

Use the OpenJDK developer guide when working with the upstream source tree.

Example: adding an upstream patch¶

This example walks through the process of backporting an upstream fix into the Debian/Ubuntu package.

1. File or find the bug report¶

All upstream OpenJDK bugs are tracked in the JDK Bug System. Search for an existing report or file a new one. Note the bug ID (e.g. JDK-8312488).

2. Find or create the fix¶

Fixes are submitted as pull requests against the openjdk/jdk repository.

3. Extract the patch¶

Download the commit as a patch. For example:

$ wget -O debian/patches/jdk-8312488.patch \
    https://github.com/openjdk/jdk/commit/78a8a99d990dcc0b77c096bb2ca2c1bb86462e3f.patch

The file name must follow the naming convention: jdk-<bug-number>.patch for merged fixes, or jdk-<bug-number>-proposed.patch for fixes not yet merged upstream.

4. Add DEP-3 headers¶

Add the required DEP-3 headers at the top of the patch file:

Description: tools/jpackage/share/AppLauncherEnvTest.java fails with dynamically linked libstdc++
 The generated image contains libjpackageapplauncheraux.so that
 contains a destructor function dcon(). It calls already disposed
 logger, causing a crash.
Author:  Vladimir Petko <vpetko@openjdk.org>
Origin: upstream, https://github.com/openjdk/jdk/commit/78a8a99d990dcc0b77c096bb2ca2c1bb86462e3f
Bug: https://bugs.openjdk.org/browse/JDK-8312488
Reviewed-By: asemenyuk, almatvee
Last-Update: 2024-07-18
---

The key fields are:

Field	Description
`Description`	Short summary on the first line, followed by an indented longer explanation.
`Author`	The commit author.
`Origin`	`upstream, <commit-url>` for merged fixes, or `other, <pr-url>` for proposed fixes.
`Bug`	Link to the JDK Bug System entry.
`Last-Update`	Date in `YYYY-MM-DD` format.

5. Add the patch to the series¶

Append the patch file name to debian/patches/series:

$ echo jdk-8312488.patch >> debian/patches/series

Then verify that the patch applies cleanly:

$ quilt push -a

Restore the source tree:

$ quilt pop -a

OpenJDK tests¶

OpenJDK uses the jtreg testing framework. See Test OpenJDK for details on running the test suite against both a locally built source tree and an installed package.