Changelists as Operation Filters

The visual grouping that Harry sees in the output of svn status as shown in our previous section is nice, but not entirely useful. The status command is but one of many operations that he might wish to perform on his working copy. Fortunately, many of Subversion's other operations understand how to operate on changelists via the use of the --changelist option.

When provided with a --changelist option, Subversion commands will limit the scope of their operation to only those files to which a particular changelist name is assigned. If Harry now wants to see the actual changes he's made to the files in his math-fixes changelist, he could explicitly list only the files that make up that changelist on the svn diff command line.

$ svn diff integer.c mathops.c
Index: integer.c
===================================================================
--- integer.c	(revision 1157)
+++ integer.c	(working copy)
…
Index: mathops.c
===================================================================
--- mathops.c	(revision 1157)
+++ mathops.c	(working copy)
…
$

That works okay for a few files, but what if Harry's change touched 20 or 30 files? That would be an annoyingly long list of explicitly named files. Now that he's using changelists, though, Harry can avoid explicitly listing the set of files in his changelist from now on, and instead provide just the changelist name:

$ svn diff --changelist math-fixes
Index: integer.c
===================================================================
--- integer.c	(revision 1157)
+++ integer.c	(working copy)
…
Index: mathops.c
===================================================================
--- mathops.c	(revision 1157)
+++ mathops.c	(working copy)
…
$

And when it's time to commit, Harry can again use the --changelist option to limit the scope of the commit to files in a certain changelist. He might commit his user interface fix by doing the following:

$ svn ci -m "Fix a UI bug found while working on math logic." \
      --changelist ui-fix
Sending        button.c
Transmitting file data .
Committed revision 1158.
$

In fact, the svn commit command provides a second changelists-related option: --keep-changelists. Normally, changelist assignments are removed from files after they are committed. But if --keep-changelists is provided, Subversion will leave the changelist assignment on the committed (and now unmodified) files. In any case, committing files assigned to one changelist leaves other changelists undisturbed.

$ svn status

--- Changelist 'math-fixes':
M      integer.c
M      mathops.c
$

Note

The --changelist option acts only as a filter for Subversion command targets, and will not add targets to an operation. For example, on a commit operation specified as svn commit /path/to/dir, the target is the directory /path/to/dir and its children (to infinite depth). If you then add a changelist specifier to that command, only those files in and under /path/to/dir that are assigned that changelist name will be considered as targets of the commit—the commit will not include files located elsewhere (such is in /path/to/another-dir), regardless of their changelist assignment, even if they are part of the same working copy as the operation's target(s).

Even the svn changelist command accepts the --changelist option. This allows you to quickly and easily rename or remove a changelist:

$ svn changelist math-bugs --changelist math-fixes --depth infinity
svn: warning: Removing 'integer.c' from changelist 'math-fixes'.
Path 'integer.c' is now a member of changelist 'math-bugs'.
svn: warning: Removing 'mathops.c' from changelist 'math-fixes'.
Path 'mathops.c' is now a member of changelist 'math-bugs'.
$ svn changelist --remove --changelist math-bugs --depth infinity
Path 'integer.c' is no longer a member of a changelist.
Path 'mathops.c' is no longer a member of a changelist.
$

Finally, you can specify multiple instances of the --changelist option on a single command line. Doing so limits the operation you are performing to files found in any of the specified changesets.