[PATCH] patch.bbclass: conditional patch-tool dependency

[Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>]

only depend do_patch on patch-tool if recipe references any patch

Signed-off-by: Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>
---
 classes/patch.bbclass |   21 +++++++++++++++++++--
 1 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/classes/patch.bbclass b/classes/patch.bbclass
index 7629e9a..1cfe24c 100644
--- a/classes/patch.bbclass
+++ b/classes/patch.bbclass
@@ -38,7 +38,7 @@ python patch_do_patch() {
 	src_uri = d.getVar("SRC_URI", True).split()
 	srcurldata = bb.fetch.init(src_uri, d, True)
 	workdir = bb.data.getVar('WORKDIR', d, 1)
-	for url in d.getVar("SRC_URI", True).split():
+	for url in src_uri:
 		urldata = srcurldata[url]
 
 		local = urldata.localpath
@@ -120,8 +120,25 @@ python patch_do_patch() {
 			bb.fatal(str(exc))
 }
 
+def patch_deps(d):
+    import oe.unpack
+
+    src_uri = d.getVar("SRC_URI", True).split()
+    srcurldata = bb.fetch.init(src_uri, d, True)
+    for url in src_uri:
+        urldata = srcurldata[url]
+        local = urldata.localpath
+        if local:
+            base, ext = os.path.splitext(os.path.basename(local))
+            if ext in ('.gz', '.bz2', '.Z', '.xz'):
+                local = base
+            if oe.unpack.is_patch(local, urldata.parm):
+                return "${PATCHDEPENDENCY}"
+    return ""
+        
+
 addtask patch after do_unpack
 do_patch[dirs] = "${WORKDIR}"
-do_patch[depends] = "${PATCHDEPENDENCY}"
+do_patch[depends] = "${@patch_deps(d)}"
 
 EXPORT_FUNCTIONS do_patch
-- 
1.7.2.3