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

Reply via email to