Allow virtual paths to specify empty source tree root folders

src/base/tree.lua

@@ -31,11 +31,13 @@
 --    The tree to contain the new node.
 -- @param p
 --    The path of the new node.
+-- @param extraFields
+--    A table containing key-value pairs to be added to any new nodes.
 -- @returns
 --    The new tree node.
 --
 
-	function tree.add(tr, p)
+	function tree.add(tr, p, extraFields)
 		-- Special case "." refers to the current node
 		if p == "." then
 			return tr
@@ -43,7 +45,7 @@
 
 		-- Look for the immediate parent for this new node, creating it if necessary.
 		-- Recurses to create as much of the tree as necessary.
-		local parentnode = tree.add(tr, path.getdirectory(p), onaddfunc)
+		local parentnode = tree.add(tr, path.getdirectory(p), extraFields)
 
 		-- Create the child if necessary
 		local childname = path.getname(p)
@@ -51,6 +53,11 @@
 		if not childnode or childnode.path ~= p then
 			childnode = tree.insert(parentnode, tree.new(childname))
 			childnode.path = p
+			if extraFields then
+				for k,v in pairs(extraFields) do
+					childnode[k] = v
+				end
+			end
 		end
 
 		return childnode
@@ -275,7 +282,7 @@
 			local node = tr.children[1]
 
 			-- if this node has no children (it is the last node in the tree) I'm done
-			if #node.children == 0 then
+			if #node.children == 0 or node.trim == false then
 				break
 			end
 

src/project/project.lua

@@ -722,13 +722,22 @@
 			-- in the IDE, not the physical organization of the file system. So
 			-- virtual paths are used when adding nodes.
 
+			-- If the project script specifies a virtual path for a file, disable
+			-- the logic that could trim out empty root nodes from that path. If
+			-- the script writer wants an empty root node they should get it.
+
+			local flags
+			if fcfg.vpath ~= fcfg.relpath then
+				flags = { trim = false }
+			end
+
 			-- Virtual paths can overlap, potentially putting files with the same
 			-- name in the same folder, even though they have different paths on
 			-- the underlying filesystem. The tree.add() call won't overwrite
 			-- existing nodes, so provide the extra logic here. Start by getting
 			-- the parent folder node, creating it if necessary.
 
-			local parent = tree.add(tr, path.getdirectory(fcfg.vpath))
+			local parent = tree.add(tr, path.getdirectory(fcfg.vpath), flags)
 			local node = tree.insert(parent, tree.new(path.getname(fcfg.vpath)))
 
 			-- Pass through value fetches to the file configuration

tests/base/test_tree.lua

@@ -267,3 +267,20 @@
 		tree.trimroot(tr)
 		test.isequal("tests", tr.children[1].path)
 	end
+
+
+--
+-- Nodes with the key "trim" set to false should be removed.
+--
+
+	function suite.trimroot_respectsTrimFlag()
+		local n = tree.add(tr, "A")
+		tree.add(tr, "A/1")
+		n.trim = false
+		tree.trimroot(tr)
+		prepare()
+		test.capture [[
+		A
+			1
+		]]
+	end