[PATCH v4] fetch/gitsm: avoid live submodule fetching during unpack()

[Matt Hoosier <matt.hoosier@gmail.com>]

Although the submodules' histories have been fetched during the
do_fetch() phase, the mechanics used to clone the workdir copy
of the repo haven't been transferring the actual .git/modules
directory from the repo fetched into downloads/ during the
fetch task.

Fix that, and for good measure also explicitly tell Git to avoid
hitting the network during do_unpack() of the submodules.

[YOCTO #12739]

Signed-off-by: Matt Hoosier <matt.hoosier@gmail.com>
---
 lib/bb/fetch2/gitsm.py | 28 +++++++++++++++++++++++++++-
 1 file changed, 27 insertions(+), 1 deletion(-)

diff --git a/lib/bb/fetch2/gitsm.py b/lib/bb/fetch2/gitsm.py
index 0aff1008..c5019e98 100644
--- a/lib/bb/fetch2/gitsm.py
+++ b/lib/bb/fetch2/gitsm.py
@@ -132,4 +132,30 @@ class GitSM(Git):
 
         if self.uses_submodules(ud, d, ud.destdir):
             runfetchcmd(ud.basecmd + " checkout " + ud.revisions[ud.names[0]], d, workdir=ud.destdir)
-            runfetchcmd(ud.basecmd + " submodule update --init --recursive", d, workdir=ud.destdir)
+
+            updateflags = ""
+
+            # Copy over the submodules' fetched histories too.
+            if ud.bareclone:
+                repo_conf = ud.destdir
+            else:
+                repo_conf = os.path.join(ud.destdir, '.git')
+
+            if os.path.exists(ud.clonedir):
+                # This is not a copy unpacked from a shallow mirror clone. So
+                # the manual intervention to populate the .git/modules done
+                # in clone_shallow_local() won't have been done yet.
+                runfetchcmd("cp -fpPRH %s %s" % (os.path.join(ud.clonedir, 'modules'), repo_conf), d)
+                updateflags += " --no-fetch"
+            elif os.path.exists(os.path.join(repo_conf, 'modules')):
+                # Unpacked from a shallow mirror clone. Manual population of
+                # .git/modules is already done.
+                updateflags += " --no-fetch"
+            else:
+                # This isn't fatal; git-submodule will just fetch it
+                # during do_unpack().
+                bb.error("submodule history not retrieved during do_fetch()")
+
+            # Careful not to hit the network during unpacking; all history should already
+            # be fetched.
+            runfetchcmd(ud.basecmd + " submodule update --init --recursive %s" % updateflags, d, workdir=ud.destdir)
-- 
2.13.6