Add slide on merge --abort

branching/branching.tex

@@ -491,7 +491,7 @@ $ emacs README
 \end{frame}
 
 \begin{frame}[fragile]
-  \frametitle{Resolving a merge conflict (1/2)}
+  \frametitle{Resolving a merge conflict (2/2)}
   We resolve the conflict by hand.
   \bigskip
   \begin{lstlisting}
@@ -513,6 +513,30 @@ $ git commit
   \end{lstlisting}
 \end{frame}
 
+\begin{frame}[fragile]
+  \frametitle{Aborting a merge}
+  If you don't feel like resolving the merge conflict, you can go back with
+  \bt{git merge --abort}.
+  \bigskip
+  \begin{lstlisting}
+$ git merge simpsons
+Auto-merging README
+CONFLICT (content): Merge conflict in README
+Automatic merge failed; fix conflicts and then
+commit the result.
+  \end{lstlisting}
+  \bigskip
+  \begin{lstlisting}
+$ git merge --abort
+  \end{lstlisting}
+  \bigskip
+  \begin{lstlisting}
+$ git status
+# On branch master
+nothing to commit (working directory clean)
+  \end{lstlisting}
+\end{frame}
+
 \begin{frame}[fragile]
   \frametitle{Resolving conflicts with \bt{git mergetool}}
   We can also use graphical merge tools such as {\em Meld}.