git-p4: add test case for "Translation of file content failed" error

A P4 repository can get into a state where it contains a file with
type UTF-16 that does not contain a valid UTF-16 BOM. If git-p4
attempts to retrieve the file then the process crashes with a
"Translation of file content failed" error.

More info here: http://answers.perforce.com/articles/KB/3117

Signed-off-by: Lars Schneider <larsxschneider@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t9825-git-p4-handle-utf16-without-bom.sh

@@ -0,0 +1,50 @@
+#!/bin/sh
+
+test_description='git p4 handling of UTF-16 files without BOM'
+
+. ./lib-git-p4.sh
+
+UTF16="\227\000\227\000"
+
+test_expect_success 'start p4d' '
+	start_p4d
+'
+
+test_expect_success 'init depot with UTF-16 encoded file and artificially remove BOM' '
+	(
+		cd "$cli" &&
+		printf "$UTF16" >file1 &&
+		p4 add -t utf16 file1 &&
+		p4 submit -d "file1"
+	) &&
+
+	(
+		cd db &&
+		p4d -jc &&
+		# P4D automatically adds a BOM. Remove it here to make the file invalid.
+		sed -e "\$d" depot/file1,v >depot/file1,v.new &&
+		mv depot/file1,v.new depot/file1,v &&
+		printf "@$UTF16@" >>depot/file1,v &&
+		p4d -jrF checkpoint.1
+	)
+'
+
+test_expect_failure 'clone depot with invalid UTF-16 file in verbose mode' '
+	git p4 clone --dest="$git" --verbose //depot &&
+	test_when_finished cleanup_git &&
+	(
+		cd "$git" &&
+		printf "$UTF16" >expect &&
+		test_cmp_bin expect file1
+	)
+'
+
+test_expect_failure 'clone depot with invalid UTF-16 file in non-verbose mode' '
+	git p4 clone --dest="$git" //depot
+'
+
+test_expect_success 'kill p4d' '
+	kill_p4d
+'
+
+test_done