javax.swing.text.AbstractDocument$BranchElement.replace(...) method throws an `ArrayIndexOutOfBoundsException: arraycopy: length -1 is negative` when using an UndoManager on the default document of a JTextArea and you try to undo the insertion of a LEFT-TO-RIGHT language (e.g. Arabic) that is immediately followed by setting the component orientation on the JTextArea.
This is because System.arrayCopy() is called with -ve length because of the calculation done in AbstractDocment.replace where `src` is of 2bytes because of unicode text causing `nmove` to become -ve if `nchildren` is 1 (an unicode character is inserted) System.arrayCopy throws `IndexOutOfBoundsException if: The srcPos argument is negative. The destPos argument is negative. The length argument is negative so the fix is made to make nmove, src, dest +ve Also, Element.getElement() can return null which is not checked, causing NPE, if deletion of text is done which results in no element, which is also fixed in the PR All jtreg testsuite tests are run without any regression. ------------- Commit messages: - Test fix - 5080391: ArrayIndexOutOfBounds during undo of Left-to-Right text insert Changes: https://git.openjdk.org/jdk/pull/10446/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=10446&range=00 Issue: https://bugs.openjdk.org/browse/JDK-5080391 Stats: 88 lines in 2 files changed: 84 ins; 0 del; 4 mod Patch: https://git.openjdk.org/jdk/pull/10446.diff Fetch: git fetch https://git.openjdk.org/jdk pull/10446/head:pull/10446 PR: https://git.openjdk.org/jdk/pull/10446