Merge branch 'ap/merge-backend-opts'

* ap/merge-backend-opts:
  Document that merge strategies can now take their own options
  Extend merge-subtree tests to test -Xsubtree=dir.
  Make "subtree" part more orthogonal to the rest of merge-recursive.
  pull: Fix parsing of -X<option>
  Teach git-pull to pass -X<option> to git-merge
  git merge -X<option>
  git-merge-file --ours, --theirs

Conflicts:
	git-compat-util.h

3 files changed, 43 insertions, 3 deletions

diff --git a/Documentation/git-merge-file.txt b/Documentation/git-merge-file.txt
index fa723d0513..234269ae59 100644
--- a/Documentation/git-merge-file.txt
+++ b/Documentation/git-merge-file.txt
@@ -10,7 +10,8 @@ SYNOPSIS
 --------
 [verse]
 'git merge-file' [-L <current-name> [-L <base-name> [-L <other-name>]]]
-	[-p|--stdout] [-q|--quiet] <current-file> <base-file> <other-file>
+	[--ours|--theirs] [-p|--stdout] [-q|--quiet]
+	<current-file> <base-file> <other-file>
 
 
 DESCRIPTION
@@ -34,7 +35,9 @@ normally outputs a warning and brackets the conflict with lines containing
 	>>>>>>> B
 
 If there are conflicts, the user should edit the result and delete one of
-the alternatives.
+the alternatives.  When `--ours` or `--theirs` option is in effect, however,
+these conflicts are resolved favouring lines from `<current-file>` or
+lines from `<other-file>` respectively.
 
 The exit value of this program is negative on error, and the number of
 conflicts otherwise. If the merge was clean, the exit value is 0.
@@ -62,6 +65,11 @@ OPTIONS
 -q::
 	Quiet; do not warn about conflicts.
 
+--ours::
+--theirs::
+	Instead of leaving conflicts in the file, resolve conflicts
+	favouring our (or their) side of the lines.
+
 
 EXAMPLES
 --------
diff --git a/Documentation/merge-options.txt b/Documentation/merge-options.txt
index 5064bf83fa..3b83dba1a0 100644
--- a/Documentation/merge-options.txt
+++ b/Documentation/merge-options.txt
@@ -74,3 +74,8 @@ option can be used to override --squash.
 -v::
 --verbose::
 	Be verbose.
+
+-X <option>::
+--strategy-option=<option>::
+	Pass merge strategy specific option through to the merge
+	strategy.
diff --git a/Documentation/merge-strategies.txt b/Documentation/merge-strategies.txt
index 42910a3d5e..a5bc1dbb95 100644
--- a/Documentation/merge-strategies.txt
+++ b/Documentation/merge-strategies.txt
@@ -1,6 +1,11 @@
 MERGE STRATEGIES
 ----------------
 
+The merge mechanism ('git-merge' and 'git-pull' commands) allows the
+backend 'merge strategies' to be chosen with `-s` option.  Some strategies
+can also take their own options, which can be passed by giving `-X<option>`
+arguments to 'git-merge' and/or 'git-pull'.
+
 resolve::
 	This can only resolve two heads (i.e. the current branch
 	and another branch you pulled from) using a 3-way merge
@@ -20,6 +25,27 @@ recursive::
 	Additionally this can detect and handle merges involving
 	renames.  This is the default merge strategy when
 	pulling or merging one branch.
++
+The 'recursive' strategy can take the following options:
+
+ours;;
+	This option forces conflicting hunks to be auto-resolved cleanly by
+	favoring 'our' version.  Changes from the other tree that do not
+	conflict with our side are reflected to the merge result.
++
+This should not be confused with the 'ours' merge strategy, which does not
+even look at what the other tree contains at all.  It discards everything
+the other tree did, declaring 'our' history contains all that happened in it.
+
+theirs;;
+	This is opposite of 'ours'.
+
+subtree[=path];;
+	This option is a more advanced form of 'subtree' strategy, where
+	the strategy makes a guess on how two trees must be shifted to
+	match with each other when merging.  Instead, the specified path
+	is prefixed (or stripped from the beginning) to make the shape of
+	two trees to match.
 
 octopus::
 	This resolves cases with more than two heads, but refuses to do
@@ -33,7 +59,8 @@ ours::
 	merge is always that of the current branch head, effectively
 	ignoring all changes from all other branches.  It is meant to
 	be used to supersede old development history of side
-	branches.
+	branches.  Note that this is different from the -Xours option to
+	the 'recursive' merge strategy.
 
 subtree::
 	This is a modified recursive strategy. When merging trees A and