====== Release cycle with subversion ======

Quick recipe/self-reminder of how I handle branching/merging on releases. Premises:
  * Trunk contains last release
  * All development goes in branches
    * Upon release, branch gets merged to trunk and then removed
  * Each release has a corresponding tag
  * Tags are never modified

Legend: ''[x] $'' marks directory from which to run –''wcopy'' for working copy–, for ''$'' directory doesn't matter

===== Cycle =====

Work on branch:
          $ svn co url://.../branches/BRANCH_X
  [wcopy] $ svn ci

"Promote" branch to trunk:
  [wcopy] $ svn ci -m "Last commit before merge"
  [wcopy] $ svn log --verbose --stop-on-copy   # Identify branching revision, e.g. 1600
  [wcopy] $ svn sw url://.../TRUNK             # Working copy changes to trunk
  [wcopy] $ svn update                         # Get HEAD revision, e.g. 1700
  [wcopy] $ svn merge -r1600:HEAD url://.../branches/BRANCH_X .
          (Fix conflicts, if any)
  [wcopy] $ svn ci -m "Merge from branch X to trunk, r1600:1700" # Logging the revision range will be useful for future 'svn log'

Incremental merges: Subsequent merges from the same branch should skip revisions already merged (i.e. "-r 1701:HEAD")

"Release":
          $ svn copy url://.../TRUNK url://.../TAGS/RELEASE_X -m "Release X"
          $ svn rm url://.../BRANCHES/BRANCH_H -m "Delete merged branch"
          $ svn copy url://.../TRUNK url://.../BRANCHES/BRANCH_Y -m "Branch Y"
  [wcopy] $ svn sw url://.../BRANCHES/BRANCH_Y              # Switch to new branch for development
         
          $ svn export url://.../TAGS/RELEASE_X X
     [X]   (package, etc. to actually release)
The tree will retain merge information (source branches and revisions), display with:
  [wcopy] $ svn pg svn:mergeinfo

===== Unclean merge =====

When branching and merging hasn't been handled too well, this can help:

  [trunk] $ svn merge --reintegrate url://.../BRANCHES/BRANCH_X .

===== Notes =====

  * ''svn merge'' acts as a normal diff.
  * ''svn merge -r R1:R2'' acts as a three-way diff.
  * Notice the dot at the end of ''merge'' lines
  * FIXME: Backporting still untested

Ref: http://svnbook.red-bean.com/en/1.0/ch04s04.html