Merge branch 'nd/gc-aggressive'

Allow tweaking the maximum length of the delta-chain produced by
"gc --aggressive".

* nd/gc-aggressive:
  environment.c: fix constness for odb_pack_keep()
  gc --aggressive: make --depth configurable

Documentation/config.txt

@@ -1156,6 +1156,11 @@ filter.<driver>.smudge::
 	object to a worktree file upon checkout.  See
 	linkgit:gitattributes[5] for details.
 
+gc.aggressiveDepth::
+	The depth parameter used in the delta compression
+	algorithm used by 'git gc --aggressive'.  This defaults
+	to 250.
+
 gc.aggressiveWindow::
 	The window size parameter used in the delta compression
 	algorithm used by 'git gc --aggressive'.  This defaults

Documentation/git-gc.txt

@@ -124,6 +124,9 @@ the value, the more time is spent optimizing the delta compression.  See
 the documentation for the --window' option in linkgit:git-repack[1] for
 more details.  This defaults to 250.
 
+Similarly, the optional configuration variable 'gc.aggressiveDepth'
+controls --depth option in linkgit:git-repack[1]. This defaults to 250.
+
 The optional configuration variable 'gc.pruneExpire' controls how old
 the unreferenced loose objects have to be before they are pruned.  The
 default is "2 weeks ago".