Merge branch 'tb/enable-cruft-packs-by-default'

When "gc" needs to retain unreachable objects, packing them into
cruft packs (instead of exploding them into loose object files) has
been offered as a more efficient option for some time.  Now the use
of cruft packs has been made the default and no longer considered
an experimental feature.

* tb/enable-cruft-packs-by-default:
  repository.h: drop unused `gc_cruft_packs`
  builtin/gc.c: make `gc.cruftPacks` enabled by default
  t/t9300-fast-import.sh: prepare for `gc --cruft` by default
  t/t6500-gc.sh: add additional test cases
  t/t6500-gc.sh: refactor cruft pack tests
  t/t6501-freshen-objects.sh: prepare for `gc --cruft` by default
  t/t5304-prune.sh: prepare for `gc --cruft` by default
  builtin/gc.c: ignore cruft packs with `--keep-largest-pack`
  builtin/repack.c: fix incorrect reference to '-C'
  pack-write.c: plug a leak in stage_tmp_packfiles()

4 files changed, 15 insertions, 16 deletions

diff --git a/Documentation/config/feature.txt b/Documentation/config/feature.txt
index e52bc6b858..17b4d39f89 100644
--- a/Documentation/config/feature.txt
+++ b/Documentation/config/feature.txt
@@ -14,9 +14,6 @@ feature.experimental::
 +
 * `fetch.negotiationAlgorithm=skipping` may improve fetch negotiation times by
 skipping more commits at a time, reducing the number of round trips.
-+
-* `gc.cruftPacks=true` reduces disk space used by unreachable objects during
-garbage collection, preventing loose object explosions.
 
 feature.manyFiles::
 	Enable config options that optimize for repos with many files in the
diff --git a/Documentation/config/gc.txt b/Documentation/config/gc.txt
index 38fea076a2..7f95c866e1 100644
--- a/Documentation/config/gc.txt
+++ b/Documentation/config/gc.txt
@@ -43,11 +43,11 @@ gc.autoDetach::
 	if the system supports it. Default is true.
 
 gc.bigPackThreshold::
-	If non-zero, all packs larger than this limit are kept when
-	`git gc` is run. This is very similar to `--keep-largest-pack`
-	except that all packs that meet the threshold are kept, not
-	just the largest pack. Defaults to zero. Common unit suffixes of
-	'k', 'm', or 'g' are supported.
+	If non-zero, all non-cruft packs larger than this limit are kept
+	when `git gc` is run. This is very similar to
+	`--keep-largest-pack` except that all non-cruft packs that meet
+	the threshold are kept, not just the largest pack. Defaults to
+	zero. Common unit suffixes of 'k', 'm', or 'g' are supported.
 +
 Note that if the number of kept packs is more than gc.autoPackLimit,
 this configuration variable is ignored, all packs except the base pack
@@ -84,7 +84,7 @@ gc.packRefs::
 gc.cruftPacks::
 	Store unreachable objects in a cruft pack (see
 	linkgit:git-repack[1]) instead of as loose objects. The default
-	is `false`.
+	is `true`.
 
 gc.pruneExpire::
 	When 'git gc' is run, it will call 'prune --expire 2.weeks.ago'
diff --git a/Documentation/git-gc.txt b/Documentation/git-gc.txt
index a65c9aa62d..90806fd26a 100644
--- a/Documentation/git-gc.txt
+++ b/Documentation/git-gc.txt
@@ -54,9 +54,10 @@ other housekeeping tasks (e.g. rerere, working trees, reflog...) will
 be performed as well.
 
 
---cruft::
+--[no-]cruft::
 	When expiring unreachable objects, pack them separately into a
-	cruft pack instead of storing them as loose objects.
+	cruft pack instead of storing them as loose objects. `--cruft`
+	is on by default.
 
 --prune=<date>::
 	Prune loose objects older than date (default is 2 weeks ago,
@@ -77,9 +78,10 @@ be performed as well.
 	instance running on this repository.
 
 --keep-largest-pack::
-	All packs except the largest pack and those marked with a
-	`.keep` files are consolidated into a single pack. When this
-	option is used, `gc.bigPackThreshold` is ignored.
+	All packs except the largest non-cruft pack, any packs marked
+	with a `.keep` file, and any cruft pack(s) are consolidated into
+	a single pack. When this option is used, `gc.bigPackThreshold`
+	is ignored.
 
 AGGRESSIVE
 ----------
diff --git a/Documentation/gitformat-pack.txt b/Documentation/gitformat-pack.txt
index e06af02f21..0c1be2dbe8 100644
--- a/Documentation/gitformat-pack.txt
+++ b/Documentation/gitformat-pack.txt
@@ -611,8 +611,8 @@ result of repeatedly resetting the objects' mtimes to the present time.
 
 If you are GC-ing repositories in a mixed version environment, consider omitting
 the `--cruft` option when using linkgit:git-repack[1] and linkgit:git-gc[1], and
-leaving the `gc.cruftPacks` configuration unset until all writers understand
-cruft packs.
+setting the `gc.cruftPacks` configuration to "false" until all writers
+understand cruft packs.
 
 === Alternatives