Merge pull request #153 from mbolivar/fix-subtree-merge

Improve subtree merge command line.

Author: ben

book/07-git-tools/sections/subtree-merges.asc

@@ -66,13 +66,12 @@ $ git pull
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 Then, we can merge those changes back into our `master` branch.
-We can use `git merge -s subtree` and it will work fine; but Git will also merge the histories together, which we probably don’t want.
-To pull in the changes and prepopulate the commit message, use the `--squash` and `--no-commit` options as well as the `-s subtree` strategy option:
+To pull in the changes and prepopulate the commit message, use the `--squash` and `--no-commit` options, as well as the recursive merge strategy's `-Xsubtree` option. (The recursive strategy is the default here, but we include it for clarity.)
 
 [source,console]
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 $ git checkout master
-$ git merge --squash -s subtree --no-commit rack_branch
+$ git merge --squash -s recursive -Xsubtree=rack --no-commit rack_branch
 Squash commit -- not updating HEAD
 Automatic merge went well; stopped before committing as requested
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