[PATCH] dpkg: warn when S equals WORKDIR

[Henning Schild <henning.schild@siemens.com>]

From: Henning Schild <henning.schild@siemens.com>

This patch does not change any logic, it just introduces a warning. If S
is not a directory inside WORKDIR do_deploy_deb and repo_clean will not
actually find any "*.deb" because they remain inside buildchroot.
Finding debs relative to BUILDROOT instead of S would require mounting
and locking. Intead of doing all of that document the small
limitation/assumption with a warning.

Signed-off-by: Henning Schild <henning.schild@siemens.com>
---
 meta/classes/dpkg-base.bbclass | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/meta/classes/dpkg-base.bbclass b/meta/classes/dpkg-base.bbclass
index 742b8ad..e31dd8d 100644
--- a/meta/classes/dpkg-base.bbclass
+++ b/meta/classes/dpkg-base.bbclass
@@ -45,9 +45,12 @@ do_apt_fetch[lockfiles] += "${REPO_ISAR_DIR}/isar.lock"
 do_apt_fetch[stamp-extra-info] = "${DISTRO}-${DISTRO_ARCH}"
 
 def get_package_srcdir(d):
-    s = d.getVar("S", True)
-    workdir = d.getVar("WORKDIR", True)
-    if s.startswith(workdir):
+    s = os.path.abspath(d.getVar("S", True))
+    workdir = os.path.abspath(d.getVar("WORKDIR", True))
+    if os.path.commonpath([s, workdir]) == workdir:
+        if s == workdir:
+            bb.warn('S is not a subdir of WORKDIR debian package operations' +
+                    ' will not work for this recipe.')
         return s[len(workdir)+1:]
     bb.warn('S does not start with WORKDIR')
     return s
-- 
2.21.0