patch.py: Prevent git repo reinitialization

There were few bugs in the _isInitialized() function which might trigger
git repo to be reinitialized and patches failing to apply.

(From OE-Core rev: 80500ecda4c1bc8812e6e078b6b0db5ec46624de)

Signed-off-by: Pavel Zhukov <pavel.zhukov@huawei.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta-selftest/recipes-test/gitrepotest/gitrepotest.bb

@@ -0,0 +1,16 @@
+SUMMARY = "Test recipe for git repo initialization"
+HOMEPAGE = "https://git.yoctoproject.org/git/matchbox-panel-2"
+LICENSE = "GPL-2.0-or-later"
+LIC_FILES_CHKSUM = "file://COPYING;md5=94d55d512a9ba36caa9b7df079bae19f"
+
+INHIBIT_DEFAULT_DEPS = "1"
+
+PATCHTOOL="git"
+
+SRC_URI = "git://git.yoctoproject.org/git/matchbox-panel-2;branch=master;protocol=https \
+           file://0001-testpatch.patch \
+          "
+
+SRCREV = "f82ca3f42510fb3ef10f598b393eb373a2c34ca7"
+
+S = "${WORKDIR}/git"

meta-selftest/recipes-test/gitrepotest/gitrepotest/0001-testpatch.patch

@@ -0,0 +1,9 @@
+diff --git a/Makefile.am b/Makefile.am
+index 432a9b4..bbf7c74 100644
+--- a/Makefile.am
++++ b/Makefile.am
+@@ -1,3 +1,4 @@
++## This is useless comment to test if patch works
+ ACLOCAL_AMFLAGS = -I m4
+ 
+ SUBDIRS = matchbox-panel applets data po