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Bug 359452

Summary:

[DataBinding] Master/Detail with DuplexingObservableValue: Incorrect Update of Detail after Edit

Product:

[Eclipse Project] Platform

Reporter:

Yoshi <kacifro>

Component:

Assignee:

Platform UI Triaged <platform-ui-triaged>

Status:

CLOSED WONTFIX

QA Contact:

Severity:

normal

Priority:

Version:

4.2

Target Milestone:

---

Hardware:

OS:

Linux

Whiteboard:

stalebug

Attachments:

Description	Flags
JUnit 4 test case	none
Proposed fix	none
Stipped-down test case	none

Description Yoshi

2011-09-29 12:16:45 EDT

Build Identifier: M20100909-0800

Hi

Cf. steps to reproduce.

Pardon me if I'm missing something obvious...

Reproducible: Always

Steps to Reproduce:
1. Launch Snippet028DuplexingObservableValue.java.
2. Select the table row "Indiana Jones and the Kingdom of the Crystal Skull".
3. In the detail part, edit "Director" from "Steven Spielberg" to "xxx"; verify that this change is reflected in the master table.
4. Select the table row "Raiders of the Lost Ark". In the detail part, "xxx" shows up as "Director" instead of the expected "Steven Spielberg".

Comment 1 Yoshi

2011-10-04 10:06:17 EDT

Created attachment 204512 [details]
JUnit 4 test case

Comment 2 Yoshi

2011-10-04 10:06:59 EDT

Created attachment 204513 [details]
Proposed fix

Comment 3 Yoshi

2011-10-04 10:08:31 EDT

Hello

It seems that the failure to update the text field has to do with a ValueChangeEvent, fired from DuplexingObservableValue, that contains a ValueDiff which in turn contains the same value ("Steven Spielberg" in the example) as both the old and new value, which makes the governing ValueBinding ignore the update of the Text field.

Ultimately, the bogus ValueDiff boils down to a stale value of the field DuplexingObservableValue.cachedValue. A fix would be to set said field in DuplexingObservableValue.doSetValue(Object).

Cf. attached JUnit test case and patch.

Regards

Comment 4 Yoshi

2011-10-12 12:51:20 EDT

Created attachment 205049 [details]
Stipped-down test case

Hello

Obsoleting the previously attached stand-alone test case, I'm enclosing a patch to DuplexingObservableValueTest of the plug-in org.eclipse.jface.tests.databinding, adding a test method to demonstrate the problem.

In essence, the wrong value is returned by doGetValue() if there are listeners attached and the dirty flag is not set (as would be as a result of a change of the target list).

The previously proposed patch is still valid.

Comment 5 Lars Vogel

2019-11-14 03:36:58 EST

This bug hasn't had any activity in quite some time. Maybe the problem got resolved, was a duplicate of something else, or became less pressing for some reason - or maybe it's still relevant but just hasn't been looked at yet.

If you have further information on the current state of the bug, please add it. The information can be, for example, that the problem still occurs, that you still want the feature, that more information is needed, or that the bug is (for whatever reason) no longer relevant.

If the bug is still relevant, please remove the "stalebug" whiteboard tag.