MAINT-8822: Revamp the LLManifest.prefix() calling convention.

The way prefix("path_fragment") or prefix(src="path_fragment") has always
worked is that unless you explicitly specify dst="", it adds "path_fragment"
to the source AND dest prefix stacks!

The most recent refactoring of viewer_manifest.py failed to copy CEF because
it involved prefix(src="../some lengthy path fragment") -- forgetting to
specify dst="" -- which added "../some lengthy path fragment" to the dest
prefix stack -- which put it outside the viewer install staging area
altogether.

Having been bitten too many times by forgetting to add prefix(dst=""), we
remove the necessity. The prefix() src=, build= and dst= prefix stacks are now
completely independent. Add src_dst= keyword argument for when you DO want to
add the same path fragment to both the source and dest prefix stacks.
("Explicit is better than implicit.")

Change all existing calls accordingly.

Now that the build prefix stack no longer tracks the src prefix stack, we were
failing to pick up some things from the build area because NOBODY ever used
build=, relying entirely on src= to point both to stuff in the source tree and
stuff in the build tree. Try to use build= appropriately.

If that proves too confusing, we might eliminate the separate build and
artwork (!) prefix stacks entirely, requiring callers to reset the src stack
explicitly when switching back and forth.

1 files changed, 24 insertions, 8 deletions

diff --git a/indra/lib/python/indra/util/llmanifest.py b/indra/lib/python/indra/util/llmanifest.py
index 598261e3d7..4c3d3fc217 100755
--- a/indra/lib/python/indra/util/llmanifest.py
+++ b/indra/lib/python/indra/util/llmanifest.py
@@ -375,7 +375,7 @@ class LLManifest(object):
         in the file list by path()."""
         self.excludes.append(glob)
 
-    def prefix(self, src='', build=None, dst=None):
+    def prefix(self, src='', build='', dst='', src_dst=None):
         """
         Usage:
 
@@ -385,8 +385,21 @@ class LLManifest(object):
         For the duration of the 'with' block, pushes a prefix onto the stack.
         Within that block, all relevant method calls (esp. to path()) will
         prefix paths with the entire prefix stack. Source and destination
-        prefixes can be different, though if only one is provided they are
-        both equal. To specify a no-op, use an empty string, not None.
+        prefixes are independent; if omitted (or passed as the empty string),
+        the prefix has no effect. Thus:
+
+        with self.prefix(src='foo'):
+            # no effect on dst
+
+        with self.prefix(dst='bar'):
+            # no effect on src
+
+        If you want to set both at once, use src_dst:
+
+        with self.prefix(src_dst='subdir'):
+            # same as self.prefix(src='subdir', dst='subdir')
+            # Passing src_dst makes any src or dst argument in the same
+            # parameter list irrelevant.
 
         Also supports the older (pre-Python-2.5) syntax:
 
@@ -400,10 +413,9 @@ class LLManifest(object):
         returned True specifically so that the caller could indent the
         relevant block of code with 'if', just for aesthetic purposes.
         """
-        if dst is None:
-            dst = src
-        if build is None:
-            build = src
+        if src_dst is not None:
+            src = src_dst
+            dst = src_dst
         self.src_prefix.append(src)
         self.artwork_prefix.append(src)
         self.build_prefix.append(build)
@@ -609,7 +621,6 @@ class LLManifest(object):
 
     def process_file(self, src, dst):
         if self.includes(src, dst):
-#            print src, "=>", dst
             for action in self.actions:
                 methodname = action + "_action"
                 method = getattr(self, methodname, None)
@@ -677,7 +688,11 @@ class LLManifest(object):
         # Don't recopy file if it's up-to-date.
         # If we seem to be not not overwriting files that have been
         # updated, set the last arg to False, but it will take longer.
+##      reldst = (dst[len(self.dst_prefix[0]):]
+##                if dst.startswith(self.dst_prefix[0])
+##                else dst).lstrip(r'\/')
         if os.path.exists(dst) and filecmp.cmp(src, dst, True):
+##          print "{} (skipping, {} exists)".format(src, reldst)
             return
         # only copy if it's not excluded
         if self.includes(src, dst):
@@ -687,6 +702,7 @@ class LLManifest(object):
                 if err.errno != errno.ENOENT:
                     raise
 
+##          print "{} => {}".format(src, reldst)
             shutil.copy2(src, dst)
 
     def ccopytree(self, src, dst):