How do I know if a branch has already been merged in SVN/Mercurial/Git?

git, mercurial, svn, user-interface

Solution

Type:

svn help mergeinfo

And you get:

mergeinfo: Display merge-related information.
usage: mergeinfo SOURCE[@REV] [TARGET[@REV]]

  Display information related to merges (or potential merges) between
  SOURCE and TARGET (default: '.').  If the --show-revs option
  is not provided, display revisions which have been merged from
  SOURCE to TARGET; otherwise, display the type of information
  specified by the --show-revs option.

Valid options:
  -r [--revision] ARG      : ARG (some commands also take ARG1:ARG2 range)
                             A revision argument can be one of:
                                NUMBER       revision number
                                '{' DATE '}' revision at start of the date
                                'HEAD'       latest in repository
                                'BASE'       base rev of item's working copy
                                'COMMITTED'  last commit at or before BASE
                                'PREV'       revision just before COMMITTED
  --show-revs ARG          : specify which collection of revisions to display
                             ('merged', 'eligible')

Problem

Is there any way of easily deciphering (i.e. at a glance) whether or not a branch has already previously been merged with the another branch or the trunk? The nearest I've been able to figure out is by looking at the commit notes and displaying the merged commit notes. The disadvantage with this seems to be that unless you know which branch the commit notes are imported from, there's no way to decipher which branches have already been merged or not. Edit: Is Mercurial or Git any more intuitive than SVN for this?

Original source