Wt

There appears to be a regression with WTableView's scrollTo where it can fail to scroll correctly under some circumstances. An attached test program should help demonstrate the issue. The test program includes instructions for reproducing the problem (a window height of 600px or more is recommended). Testing was done with github master 4.2.0-1-g0b709fd4.

It appears that the regression was introduced with commit 9144a445 (and is also present in 4.1.2 with commit d9e9b770). Reverting commit 9144a445 seems to fix the behavior of the test program. The issue appears to be due to stale local values of scrollTop, etc. interacting with WTableView's autoJavaScript. The behavior is timing dependent.

I've attached a patch (0001-Additional-logging-for-WTableView-scrollTo-issue.patch) that adds some console logging to WTableView that may be helpful in debugging. The autoJavaScript messages are probably the most useful, as they appear to be directly related to the failure cases.

I also tested a potential fix: 0001-Fix-intermittent-scrollTo-failures-in-WTableView.patch. However I am not able to reproduce the original issue that commit 9144a445 was intended to address, so I don't know if it handles that issue successfully.