[PATCH 1/2] patch: special-case quilt in debian

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

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

The OE patch lib uses quilt and so do many debian packages as well.
Those two do not work well together, it is really hard to create a patch
that will apply and not break what debian does later. debian is very
pedantic about unexpected changes so even if patching works, building
might not.

Introduce a special-case where we detect quilt usage of a debian package
and hook in there. Also make sure we are on top of debian so we do not
risk breaking patches we inherit from there.

If anyone ever managed to create a patch that works well in the face of
two quilts, that might break with this change. You can set PATCHTOOL to
"quilt" in your recipe to disable the magic.

Signed-off-by: Henning Schild <henning.schild@siemens.com>
---
 meta/classes/patch.bbclass | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/meta/classes/patch.bbclass b/meta/classes/patch.bbclass
index 3060755a5c..06f32a2197 100644
--- a/meta/classes/patch.bbclass
+++ b/meta/classes/patch.bbclass
@@ -91,6 +91,28 @@ def should_apply(parm, d):
 
 should_apply[vardepsexclude] = "DATE SRCDATE"
 
+def patch_do_debian_quilt(patchdir, d):
+    import oe.patch
+    class DummyPatchSet(oe.patch.PatchSet):
+        def Clean(self):
+            True
+
+        def Import(self, patch, force):
+            os.putenv('QUILT_PATCHES', 'debian/patches')
+            # push all so we are on top of debian
+            pushed = False
+            if os.path.exists(os.path.join(self.dir, 'debian/patches/series')):
+                oe.patch.runcmd(["quilt", "push", "-a"], self.dir)
+                pushed = True
+            oe.patch.runcmd(["quilt", "import", "-f", os.path.join(d.getVar('WORKDIR'), os.path.basename(patch['file']))], self.dir)
+            if pushed:
+                oe.patch.runcmd(["quilt", "pop", "-a"], self.dir)
+
+        def Push(self, force = False):
+            True
+
+    return DummyPatchSet(patchdir, d)
+
 python patch_do_patch() {
     import sys
 
@@ -118,6 +140,12 @@ python patch_do_patch() {
 
     s = d.getVar('S')
 
+    debianformat = os.path.join(s, 'debian/source/format')
+    if os.path.exists(debianformat) and d.getVar('PATCHTOOL') != 'quilt':
+        with open(debianformat, 'r+') as f:
+            if f.readline() == '3.0 (quilt)\n':
+                cls = patch_do_debian_quilt
+
     os.putenv('PATH', d.getVar('PATH'))
 
     # We must use one TMPDIR per process so that the "patch" processes
-- 
2.26.2