From 5cc09f6f8764041f77e407c3b84c63410479f24e Mon Sep 17 00:00:00 2001
From: Martijn Vermaat <martijn@vermaat.name>
Date: Sun, 13 Oct 2013 18:39:59 +0200
Subject: [PATCH] Complete slides on branching
---
branching/branching.tex | 165 +-
branching/images/meld.eps | 131726 +++++++++++++++++++++++++++++++++++
branching/images/meld.png | Bin 0 -> 120431 bytes
3 files changed, 131890 insertions(+), 1 deletion(-)
create mode 100644 branching/images/meld.eps
create mode 100644 branching/images/meld.png
diff --git a/branching/branching.tex b/branching/branching.tex
index d6ecb8d..9df2928 100644
--- a/branching/branching.tex
+++ b/branching/branching.tex
@@ -371,7 +371,170 @@ Deleted branch license (was 0fbe3e3).
\end{frame}
-% todo: basic merge conflicts, tags
+\section{Basic merge conflicts}
+
+\begin{frame}
+ \frametitle{Merge conflicts}
+ Git is pretty good at merging:
+ \begin{itemize}
+ \item The changes might have been in different files.
+ \item Or in different parts of the same file.
+ \item Git tries to figure out a sensible result.
+ \end{itemize}
+ \pause
+ \bigskip
+ Sometimes this is not possible:
+ \begin{itemize}
+ \item The changes might be incompatible.
+ \item When we try \bt{git merge}, Git gives up.
+ \item This situation is called a {\em merge conflict}.
+ \end{itemize}
+\end{frame}
+
+\begin{frame}[fragile]
+ \frametitle{Setting the stage (1/3)}
+ \begin{lstlisting}
+$ git log --oneline --decorate --graph --all
+* 9d2ad27 (HEAD, master) State character preference
+| * 374ab60 (simpsons) State character preference
+|/
+* 4012f4f Initial commit
+ \end{lstlisting}
+ \bigskip
+ We'd like to merge branch \bt{simpsons} into \bt{master}.
+\end{frame}
+
+\begin{frame}[fragile]
+ \frametitle{Setting the stage (2/3)}
+ The last commit on \bt{master}:
+ \bigskip
+ \begin{lstlisting}
+$ git show --oneline
+9d2ad27 State character preference
+diff --git a/README b/README
+index de15194..ef40359 100644
+--- a/README
++++ b/README
+@@ -1,2 +1,4 @@
+ Facts about television series
+ =============================
++
++My favorite character is Eric Cartman.
+ \end{lstlisting}
+\end{frame}
+
+\begin{frame}[fragile]
+ \frametitle{Setting the stage (3/3)}
+ The last commit on \bt{simpsons}:
+ \bigskip
+ \begin{lstlisting}
+$ git show --oneline simpsons
+374ab60 State character preference
+diff --git a/README b/README
+index de15194..9dd729b 100644
+--- a/README
++++ b/README
+@@ -1,2 +1,4 @@
+ Facts about television series
+ =============================
++
++My favorite character is Homer Simpson.
+ \end{lstlisting}
+\end{frame}
+
+\begin{frame}[fragile]
+ \frametitle{Creating a merge conflict}
+ \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 status
+# On branch master
+# Unmerged paths:
+# (use "git add/rm <file>.." as appropriate to
+# mark resolution)
+#
+# both modified: README
+#
+no changes added to commit (use "git add" and/or
+"git commit -a")
+ \end{lstlisting}
+\end{frame}
+
+\begin{frame}[fragile]
+ \frametitle{Resolving a merge conflict (1/2)}
+ \begin{lstlisting}
+$ cat README
+Facts about television series
+=============================
+
+<<<<<<< HEAD
+My favorite character is Eric Cartman.
+=======
+My favorite character is Homer Simpson.
+>>>>>>> simpsons
+ \end{lstlisting}
+ \bigskip
+ What we had is under \bt{HEAD}, what \bt{simpsons} had is above
+ \bt{simpsons}.
+ \pause
+ \bigskip
+ \begin{lstlisting}
+$ emacs README
+ \end{lstlisting}
+\end{frame}
+
+\begin{frame}[fragile]
+ \frametitle{Resolving a merge conflict (1/2)}
+ We resolve the conflict by hand.
+ \bigskip
+ \begin{lstlisting}
+$ cat README
+Facts about television series
+=============================
+
+My favorite characters are Eric Cartman
+and Homer Simpson.
+ \end{lstlisting}
+ \pause
+ \bigskip
+ And can now finish the merge commit.
+ \bigskip
+ \begin{lstlisting}
+$ git add README
+$ git commit
+[master 1e496cb] Merge branch 'simpsons'
+ \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}.
+ \bigskip
+ \begin{lstlisting}
+$ git mergetool
+merge tool candidates: meld opendiff kdiff3 ...
+Merging:
+README
+
+Normal merge conflict for 'README':
+ {local}: modified file
+ {remote}: modified file
+Hit return to start merge resolution tool (meld):
+ \end{lstlisting}
+\end{frame}
+
+\begin{frame}
+ \frametitle{Meld example}
+ \includegraphics[width=11cm]{images/meld}\\
+ \vspace{0.5cm}
+ Tools like Meld provide an editable three-way diff.
+\end{frame}
\section{Questions?}
diff --git a/branching/images/meld.eps b/branching/images/meld.eps
new file mode 100644
index 0000000..746e645
--- /dev/null
+++ b/branching/images/meld.eps
@@ -0,0 +1,131726 @@
+%!PS-Adobe-3.0 EPSF-3.0
+%%Creator: (ImageMagick)
+%%Title: (meld.eps)
+%%CreationDate: (2013-10-13T18:37:16+02:00)
+%%BoundingBox: -0 -0 1920 890
+%%HiResBoundingBox: 0 0 1919.73 890
+%%DocumentData: Clean7Bit
+%%LanguageLevel: 1
+%%Pages: 1
+%%EndComments
+
+%%BeginDefaults
+%%EndDefaults
+
+%%BeginProlog
+%
+% Display a color image. The image is displayed in color on
+% Postscript viewers or printers that support color, otherwise
+% it is displayed as grayscale.
+%
+/DirectClassPacket
+{
+ %
+ % Get a DirectClass packet.
+ %
+ % Parameters:
+ % red.
+ % green.
+ % blue.
+ % length: number of pixels minus one of this color (optional).
+ %
+ currentfile color_packet readhexstring pop pop
+ compression 0 eq
+ {
+ /number_pixels 3 def
+ }
+ {
+ currentfile byte readhexstring pop 0 get
+ /number_pixels exch 1 add 3 mul def
+ } ifelse
+ 0 3 number_pixels 1 sub
+ {
+ pixels exch color_packet putinterval
+ } for
+ pixels 0 number_pixels getinterval
+} bind def
+
+/DirectClassImage
+{
+ %
+ % Display a DirectClass image.
+ %
+ systemdict /colorimage known
+ {
+ columns rows 8
+ [
+ columns 0 0
+ rows neg 0 rows
+ ]
+ { DirectClassPacket } false 3 colorimage
+ }
+ {
+ %
+ % No colorimage operator; convert to grayscale.
+ %
+ columns rows 8
+ [
+ columns 0 0
+ rows neg 0 rows
+ ]
+ { GrayDirectClassPacket } image
+ } ifelse
+} bind def
+
+/GrayDirectClassPacket
+{
+ %
+ % Get a DirectClass packet; convert to grayscale.
+ %
+ % Parameters:
+ % red
+ % green
+ % blue
+ % length: number of pixels minus one of this color (optional).
+ %
+ currentfile color_packet readhexstring pop pop
+ color_packet 0 get 0.299 mul
+ color_packet 1 get 0.587 mul add
+ color_packet 2 get 0.114 mul add
+ cvi
+ /gray_packet exch def
+ compression 0 eq
+ {
+ /number_pixels 1 def
+ }
+ {
+ currentfile byte readhexstring pop 0 get
+ /number_pixels exch 1 add def
+ } ifelse
+ 0 1 number_pixels 1 sub
+ {
+ pixels exch gray_packet put
+ } for
+ pixels 0 number_pixels getinterval
+} bind def
+
+/GrayPseudoClassPacket
+{
+ %
+ % Get a PseudoClass packet; convert to grayscale.
+ %
+ % Parameters:
+ % index: index into the colormap.
+ % length: number of pixels minus one of this color (optional).
+ %
+ currentfile byte readhexstring pop 0 get
+ /offset exch 3 mul def
+ /color_packet colormap offset 3 getinterval def
+ color_packet 0 get 0.299 mul
+ color_packet 1 get 0.587 mul add
+ color_packet 2 get 0.114 mul add
+ cvi
+ /gray_packet exch def
+ compression 0 eq
+ {
+ /number_pixels 1 def
+ }
+ {
+ currentfile byte readhexstring pop 0 get
+ /number_pixels exch 1 add def
+ } ifelse
+ 0 1 number_pixels 1 sub
+ {
+ pixels exch gray_packet put
+ } for
+ pixels 0 number_pixels getinterval
+} bind def
+
+/PseudoClassPacket
+{
+ %
+ % Get a PseudoClass packet.
+ %
+ % Parameters:
+ % index: index into the colormap.
+ % length: number of pixels minus one of this color (optional).
+ %
+ currentfile byte readhexstring pop 0 get
+ /offset exch 3 mul def
+ /color_packet colormap offset 3 getinterval def
+ compression 0 eq
+ {
+ /number_pixels 3 def
+ }
+ {
+ currentfile byte readhexstring pop 0 get
+ /number_pixels exch 1 add 3 mul def
+ } ifelse
+ 0 3 number_pixels 1 sub
+ {
+ pixels exch color_packet putinterval
+ } for
+ pixels 0 number_pixels getinterval
+} bind def
+
+/PseudoClassImage
+{
+ %
+ % Display a PseudoClass image.
+ %
+ % Parameters:
+ % class: 0-PseudoClass or 1-Grayscale.
+ %
+ currentfile buffer readline pop
+ token pop /class exch def pop
+ class 0 gt
+ {
+ currentfile buffer readline pop
+ token pop /depth exch def pop
+ /grays columns 8 add depth sub depth mul 8 idiv string def
+ columns rows depth
+ [
+ columns 0 0
+ rows neg 0 rows
+ ]
+ { currentfile grays readhexstring pop } image
+ }
+ {
+ %
+ % Parameters:
+ % colors: number of colors in the colormap.
+ % colormap: red, green, blue color packets.
+ %
+ currentfile buffer readline pop
+ token pop /colors exch def pop
+ /colors colors 3 mul def
+ /colormap colors string def
+ currentfile colormap readhexstring pop pop
+ systemdict /colorimage known
+ {
+ columns rows 8
+ [
+ columns 0 0
+ rows neg 0 rows
+ ]
+ { PseudoClassPacket } false 3 colorimage
+ }
+ {
+ %
+ % No colorimage operator; convert to grayscale.
+ %
+ columns rows 8
+ [
+ columns 0 0
+ rows neg 0 rows
+ ]
+ { GrayPseudoClassPacket } image
+ } ifelse
+ } ifelse
+} bind def
+
+/DisplayImage
+{
+ %
+ % Display a DirectClass or PseudoClass image.
+ %
+ % Parameters:
+ % x & y translation.
+ % x & y scale.
+ % label pointsize.
+ % image label.
+ % image columns &