merge, mergetool and difftool slug

Author: schacon

book/03-git-branching/sections/basic-branching-and-merging.asc

@@ -15,6 +15,7 @@ You'll do the following:
 . After it's tested, merge the hotfix branch, and push to production.
 . Switch back to your original story and continue working.
 
+[[_basic_branching]]
 ==== Basic Branching
 
 (((branches, basic workflow)))

book/05-distributed-git/sections/contributing.asc

@@ -477,7 +477,8 @@ The sequence for the workflow you saw here is something like this:
 .Basic sequence of this managed-team workflow.
 image::images/managed-team-flow.png[Basic sequence of this managed-team workflow.]
 
-==== Public Project, Fork
+[[_public_project]]
+==== Forked Public Project
 
 (((contributing, public small project)))
 Contributing to public projects is a bit different.
@@ -612,7 +613,7 @@ Now you can send the maintainer a message that you've made the requested changes
 .Commit history after `featureBv2` work.
 image::images/public-small-3.png[Commit history after `featureBv2` work.]
 
-==== Public Project, E-Mail
+==== Public Project over E-Mail
 
 (((contributing, public large project)))
 Many projects have established procedures for accepting patches – you'll need to check the specific rules for each project, because they will differ.

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

@@ -1,3 +1,4 @@
+[[_subtree_merge]]
 ===== Subtree Merging
 
 The idea of the subtree merge is that you have two projects, and one of the projects maps to a subdirectory of the other one and vice versa.

book/C-git-commands/1-git-commands.asc

@@ -103,6 +103,13 @@ We use it to filter out whitespace differences with `-w` and how to compare diff
 
 Finally, we use it to effectively compare submodule changes with `--submodule` in <<_starting_submodules>>.
 
+==== git difftool
+
+The `git difftool` command simply launches an external tool to show you the difference between two trees in case you want to use something other than the built in `git diff` command.
+
+TODO: We don't ever cover this, lol.
+
+
 ==== git commit
 
 The `git commit` command takes all the file contents that have been staged with `git add` and records a new permanant snapshot in the database and then moves the branch pointer on the current branch up to it.
@@ -171,10 +178,24 @@ Finally, we go into some implementation detail in <<_the_head>>.
 
 ==== git merge
 
-The `git merge` tool is used to merge one or more branches  into the branch you have checked out.
+The `git merge` tool is used to merge one or more branches  into the branch you have checked out. It will then advance the current branch to the result of the merge.
+
+The `git merge` command was first introduced in <<_basic_branching>>. Though it is used in various places in the book, there are very few variations of the `merge` command -- generally just `git merge <branch>` with the name of the single branch you want to merge in.
+
+We covered how to do a squashed merge (where Git merges the work but pretends like it's just a new commit without recording the history of the branch you're merging in) at the very end of <<_public_project>>.
+
+We went over a lot about the merge process and command, including the `-Xignore-all-whitespace` command and the `--abort` flag to abort a problem merge in <<_advanced_merging>>.
+
+We learned how to verify signatures before merging if your project is using GPG signing in <<_signing_commits>>.
+
+Finally, we learned about Subtree merging in <<_subtree_merge>>.
 
 ==== git mergetool
 
+The `git mergetool` command simply launches an external merge helper in case you have issues with a merge in Git.
+
+We mention it quickly in <<_basic_merge_conflicts>> and go into detail on how to implement your own external merge tool in <<_external_merge_tools>>.
+
 ==== git log
 
 ==== git stash