Add a "git show" command to show a commit

[Linus Torvalds <torvalds@osdl.org>]

It's basically just "git-diff-tree" with pretty flags and a pager.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---

This uses the "--always" flag, btw, so it depends on the previous patch I 
sent. If you disagree with that, just remove it.

This is actually something I do pretty often, and I've grown tired of 
doing

	git-diff-tree -p --pretty cmit-id | less -S

so this is really nothing but a fairly flexible replacement for that.

It tries to have the same logic as "git diff" for the flags. 

diff --git a/Makefile b/Makefile
index 2aa2385..473e58d 100644
--- a/Makefile
+++ b/Makefile
@@ -112,7 +112,7 @@ SCRIPT_SH = \
 	git-applymbox.sh git-applypatch.sh git-am.sh \
 	git-merge.sh git-merge-stupid.sh git-merge-octopus.sh \
 	git-merge-resolve.sh git-merge-ours.sh git-grep.sh \
-	git-lost-found.sh
+	git-lost-found.sh git-show.sh
 
 SCRIPT_PERL = \
 	git-archimport.perl git-cvsimport.perl git-relink.perl \
diff --git a/git-show.sh b/git-show.sh
new file mode 100644
index 0000000..476bca4
--- /dev/null
+++ b/git-show.sh
@@ -0,0 +1,23 @@
+#!/bin/sh
+
+rev=$(git-rev-parse --verify --revs-only --no-flags --sq --default HEAD "$@") || exit
+flags=$(git-rev-parse --no-revs --flags --sq "$@")
+files=$(git-rev-parse --no-revs --no-flags --sq "$@")
+
+# Match the behaviour of "git diff":
+#  - if we do not have --name-status, --name-only nor -r, default to -p.
+#  - if we do not have -B nor -C, default to -M.
+case " $flags " in
+*" '--name-status' "* | *" '--name-only' "* | *" '-r' "* )
+	;;
+*)
+	flags="$flags'-p' " ;;
+esac
+case " $flags " in
+*" '-"[BCM]* | *" '--find-copies-harder' "*)
+	;; # something like -M50.
+*)
+	flags="$flags'-M' " ;;
+esac
+
+eval "git-diff-tree --always --cc --pretty $flags $rev -- $files" | LESS=-S ${PAGER:-less}