[PATCH] git-am: Handle "git show" output correctly

[Peter Jones <pjones@redhat.com>]

This patch adds the ability for "git am" to accept patches in the format
generated by "git show".  Some people erroneously use "git show" instead
of "git format-patch", and it's nice as a maintainer to be able to
easily take their patch rather than going back and forth with them to
get a "correctly" formatted patch containing exactly the same actual
information.

Signed-off-by: Peter Jones <pjones@redhat.com>
---
 git-am.sh | 60 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 60 insertions(+)

diff --git a/git-am.sh b/git-am.sh
index c682d34..210e9fe 100755
--- a/git-am.sh
+++ b/git-am.sh
@@ -216,6 +216,21 @@ check_patch_format () {
 		read l2
 		read l3
 		case "$l1" in
+		"commit "*)
+			case "$l2" in
+			"Author: "*)
+				case "$l3" in
+				"Date: "*)
+					patch_format=gitshow
+					;;
+				*)
+					;;
+				esac
+				;;
+			*)
+				;;
+			esac
+			;;
 		"From "* | "From: "*)
 			patch_format=mbox
 			;;
@@ -321,6 +336,51 @@ split_patches () {
 		this=
 		msgnum=
 		;;
+	gitshow)
+		this=0
+		for patch in "$@"
+		do
+			this=`expr "$this" + 1`
+			msgnum=`printf "%0${prec}d" $this`
+			# The first nonemptyline after an empty line is the
+			# subject, and the body starts with the next nonempty
+			# line.
+			perl -ne 'BEGIN {
+					$diff = 0; $subject = 0; $subjtext="";
+				}
+				if ($diff == 1 || /^diff/ || /^---$/) {
+					$diff = 1 ;
+					print ;
+				} elsif ($subject > 1) {
+					s/^    // ;
+					print ;
+				} elsif ($subject == 1 && !/^\s+$/) {
+					s/^    // ;
+					$subjtext = "$subjtext $_";
+				} elsif ($subject == 1) {
+					$subject = 2 ;
+					print "Subject: ", $subjtext ;
+					s/^    // ;
+					print ;
+				} elsif ($subject) {
+					print "\n" ;
+					s/^    // ;
+					print ;
+				} elsif (/^\s+$/) { next ; }
+				elsif (/^Author:/) { s/Author/From/ ; print ;}
+				elsif (/^(From|Date)/) { print ; }
+				elsif (/^commit/) { next ; }
+				else {
+					s/^    // ;
+					$subjtext = $_;
+					$subject = 1;
+				}
+			' < "$patch" > "$dotest/$msgnum" || clean_abort
+		done
+		echo "$this" > "$dotest/last"
+		this=
+		msgnum=
+		;;
 	hg)
 		this=0
 		for hg in "$@"
-- 
1.7.11.4