Restarting workspace should take into account changes to eclipse.ini

[umairsair]

Background:

There are 3 return codes supported by Eclipse

• 0 - Normal exit
• 23 - Restart the eclipse with previous launcher arguments
• 24 - Restart the eclipse with the arguments provided by Eclipse application itself

The above mentioned problem is not with the exit code 23. The reason is that the eclipse launcher restarts itself in this case, hence eclipse.ini is also reloaded. However eclipse launcher does not restart itself in case of code 24 and parses the arguments provided by Eclipse application in shared memory and simply relaunches java, which means that eclipse.ini will not be reloaded.

For restarts, eclipse should be using code 23 but we had to switch to code 24 to fix following issue.
[WorkbenchLauncher] Restart asks for the workspace to run
And then the fix of following built up on it.
[Workspace chooser] "Older Workspace Version" dialog: "Cancel" button shouldn't close Eclipse but go back to workspace chooser

Fix:

For code 24, the arguments in shared memory are for launcher, so instead of launcher just parsing the args and relaunching java, it should restart the launcher with appropriate arguments. With relaunching the launcher, eclipse.ini will be reloaded like its done for code 23.

Eclipse launcher is updated to relaunch for code 24 as well. Moreover, there are 3 new launcher arguments introduced, 2 are internal to launcher and one is external to launcher and can be set by eclipse application as a relaunch argument.

• --launcher.oldUserArgsStart and --launcher.oldUserArgsEnd: The user arguments passed to eclipse launcher for first start are tracked between these arguments during relaunches. E.g., if eclipse was started as eclipse A B C where A B C are some arguments to launcher and for relaunch, Eclipse application mentioned X Y Z arguments then relaunch command will be eclipse --launcher.oldUserArgsStart A B C --launcher.oldUserArgsEnd A B C X Y Z. Moreover, launcher relaunch will ignore all arguments between and including --launcher.oldUserArgsStart and --launcher.oldUserArgsEnd.
• --launcher.skipOldUserArgs: If eclipse application wants to relaunch with provided arguments only and ignore the older user args then it can mention this argument. So for the case where eclipse was started as eclipse A B C and Eclipse application mentioned X Y Z as relaunch arguments along with --launcher.skipOldUserArgs then relaunch command will be
  eclipse --launcher.oldUserArgsStart A B C --launcher.oldUserArgsEnd X Y Z where launcher relaunch will ignore all arguments between and including --launcher.oldUserArgsStart and --launcher.oldUserArgsEnd.

For restarts, Eclipse application just mentions the -data argument now as relaunch arguments instead of mentioning complete java args. However, user can still mention more arguments for relaunch and Eclipse restart will respect them as well and append the -data argument at the end of user arguments.

See also eclipse-equinox/equinox#401
Fixes eclipse-equinox/p2#166

[github-actions]

Test Results

   930 files  +    1     930 suites  +1   52m 24s ⏱️ + 14m 55s
 7 474 tests ±    0   7 321 ✅ +    1  153 💤 ±  0  0 ❌  - 1 
23 571 runs  +1 578  23 060 ✅ +1 458  511 💤 +121  0 ❌  - 1 

Results for commit 31da964. ± Comparison against base commit 3c5c4bf.

♻️ This comment has been updated with latest results.

[umairsair]

@sravanlakkimsetti any comments here or are we good?