cmake: support for testing git when building out of the source tree

This patch allows git to be tested when performin out of source builds.

This involves changing GIT_BUILD_DIR in t/test-lib.sh to point to the
build directory. Also some miscellaneous copies from the source directory
to the build directory.
The copies are:
t/chainlint.sed needed by a bunch of test scripts
po/is.po needed by t0204-gettext-rencode-sanity
mergetools/tkdiff needed by t7800-difftool
contrib/completion/git-prompt.sh needed by t9903-bash-prompt
contrib/completion/git-completion.bash needed by t9902-completion
contrib/svn-fe/svnrdump_sim.py needed by t9020-remote-svn

NOTE: t/test-lib.sh is only modified when tests are run not during
the build or configure.
The trash directory is still srcdir/t

Signed-off-by: Sibi Siddharthan <sibisiddharthan.github@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: SibiSiddharthan

contrib/buildsystems/CMakeLists.txt

@@ -862,6 +862,26 @@ file(APPEND ${CMAKE_BINARY_DIR}/GIT-BUILD-OPTIONS "NO_GETTEXT='${NO_GETTEXT}'\n"
 file(APPEND ${CMAKE_BINARY_DIR}/GIT-BUILD-OPTIONS "RUNTIME_PREFIX='${RUNTIME_PREFIX}'\n")
 file(APPEND ${CMAKE_BINARY_DIR}/GIT-BUILD-OPTIONS "NO_PYTHON='${NO_PYTHON}'\n")
 
+#Make the tests work when building out of the source tree
+get_filename_component(CACHE_PATH ${CMAKE_CURRENT_LIST_DIR}/../../CMakeCache.txt ABSOLUTE)
+if(NOT ${CMAKE_BINARY_DIR}/CMakeCache.txt STREQUAL ${CACHE_PATH})
+	file(RELATIVE_PATH BUILD_DIR_RELATIVE ${CMAKE_SOURCE_DIR} ${CMAKE_BINARY_DIR}/CMakeCache.txt)
+	string(REPLACE "/CMakeCache.txt" "" BUILD_DIR_RELATIVE ${BUILD_DIR_RELATIVE})
+	#Setting the build directory in test-lib.sh before running tests
+	file(WRITE ${CMAKE_BINARY_DIR}/CTestCustom.cmake
+		"file(STRINGS ${CMAKE_SOURCE_DIR}/t/test-lib.sh GIT_BUILD_DIR_REPL REGEX \"GIT_BUILD_DIR=(.*)\")\n"
+		"file(STRINGS ${CMAKE_SOURCE_DIR}/t/test-lib.sh content NEWLINE_CONSUME)\n"
+		"string(REPLACE \"\${GIT_BUILD_DIR_REPL}\" \"GIT_BUILD_DIR=\\\"$TEST_DIRECTORY\\\"/../${BUILD_DIR_RELATIVE}\" content \"\${content}\")\n"
+		"file(WRITE ${CMAKE_SOURCE_DIR}/t/test-lib.sh \${content})")
+	#misc copies
+	file(COPY ${CMAKE_SOURCE_DIR}/t/chainlint.sed DESTINATION ${CMAKE_BINARY_DIR}/t/)
+	file(COPY ${CMAKE_SOURCE_DIR}/po/is.po DESTINATION ${CMAKE_BINARY_DIR}/po/)
+	file(COPY ${CMAKE_SOURCE_DIR}/mergetools/tkdiff DESTINATION ${CMAKE_BINARY_DIR}/mergetools/)
+	file(COPY ${CMAKE_SOURCE_DIR}/contrib/completion/git-prompt.sh DESTINATION ${CMAKE_BINARY_DIR}/contrib/completion/)
+	file(COPY ${CMAKE_SOURCE_DIR}/contrib/completion/git-completion.bash DESTINATION ${CMAKE_BINARY_DIR}/contrib/completion/)
+	file(COPY ${CMAKE_SOURCE_DIR}/contrib/svn-fe/svnrdump_sim.py DESTINATION ${CMAKE_BINARY_DIR}/contrib/svn-fe/)
+endif()
+
 file(GLOB test_scipts "${CMAKE_SOURCE_DIR}/t/t[0-9]*.sh")
 
 #test