podfix: class to remove Pod::Man versions from manpages

Manpages generated by Pod::Man contain the version number, which isn't
reproducible if we're using the host Perl to generate manpage.

One option is to always depend on perl-native when generating manpages
but this is a heavy dependency, so instead strip out the versions in
do_install().

(From OE-Core rev: 18d8e5ac689d6eb6098f68ac785f43e9d5f5938a)

Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/classes/podfix.bbclass

@@ -0,0 +1,32 @@
+python pod_strip_version() {
+    import re
+
+    def opener(filename, mode):
+        if filename.endswith(".gz"):
+            import gzip
+            return gzip.open(filename, mode)
+        elif filename.endswith(".bz2"):
+            import bz2
+            return bz2.open(filename, mode)
+        else:
+            return open(filename, mode)
+
+    bad_re = re.compile(rb"Automatically generated by Pod::Man( [0-9]+.+)")
+
+    for root, dirs, files in os.walk(d.expand("${D}${mandir}")):
+        for filename in files:
+            filename = os.path.join(root, filename)
+            with opener(filename, "rb") as manfile:
+                manpage = manfile.read()
+                m = bad_re.search(manpage)
+                if not m:
+                    continue
+
+            bb.note("podfix: stripping version from %s" % filename)
+            os.unlink(filename)
+            with opener(filename, "wb") as manfile:
+                manfile.write(manpage[:m.start(1)])
+                manfile.write(manpage[m.end(1):])
+}
+
+do_install[postfuncs] += "pod_strip_version"