staging: Fix overlapping file failures

If there are different providers of a file and they are swiched when the
recipe isn't machine specific, we can get tracebacks due to the overlapping
files. The issue is that the previous provider isn't uninstalled since
the system can't tell whether some later task needs them.

By tracking which tasks we depend upon, the code can now choose to
uninstall more things since a later task can reinstall if/as needed.

The code here was to protect against code with two different tasks
running in parallel which is still protected agaisnt.

[YOCTO #13702]

(From OE-Core rev: 86f36e3f93cdb2f5882b72e736a770aa6f46100d)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Signed-off-by: Steve Sakoman <steve@sakoman.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/classes/staging.bbclass

@@ -277,11 +277,13 @@ python extend_recipe_sysroot() {
 
     start = None
     configuredeps = []
+    owntaskdeps = []
     for dep in taskdepdata:
         data = taskdepdata[dep]
         if data[1] == mytaskname and data[0] == pn:
             start = dep
-            break
+        elif data[0] == pn:
+            owntaskdeps.append(data[1])
     if start is None:
         bb.fatal("Couldn't find ourself in BB_TASKDEPDATA?")
 
@@ -427,7 +429,7 @@ python extend_recipe_sysroot() {
                         # Was likely already uninstalled
                         continue
                     potential.append(l)
-        # We need to ensure not other task needs this dependency. We hold the sysroot
+        # We need to ensure no other task needs this dependency. We hold the sysroot
         # lock so we ca search the indexes to check
         if potential:
             for i in glob.glob(depdir + "/index.*"):
@@ -435,6 +437,11 @@ python extend_recipe_sysroot() {
                     continue
                 with open(i, "r") as f:
                     for l in f:
+                        if l.startswith("TaskDeps:"):
+                            prevtasks = l.split()[1:]
+                            if mytaskname in prevtasks:
+                                # We're a dependency of this task so we can clear items out the sysroot
+                                break
                         l = l.strip()
                         if l in potential:
                             potential.remove(l)
@@ -588,6 +595,7 @@ python extend_recipe_sysroot() {
         os.symlink(manifests[dep], depdir + "/" + c + ".complete")
 
     with open(taskindex, "w") as f:
+        f.write("TaskDeps: " + " ".join(owntaskdeps) + "\n")
         for l in sorted(installed):
             f.write(l + "\n")