When configuration settings overlap, give precedence to the later settings

src/project/oven.lua

@@ -424,11 +424,16 @@
 
 	function oven.mergetables(original, additions)
 		for _, item in ipairs(additions) do
-			-- prevent duplicates
-			if not original[item] then
-				original[item] = item
-				table.insert(original, item)
+			-- if the item is already in the list, remove it. This allows a
+			-- later configuration block (i.e. a project) to override the
+			-- ordering of values from an earlier block (i.e. a solution).
+			-- Could be a performance hit; have to wait and see.
+			if original[item] then
+				local i = table.indexof(original, item)
+				table.remove(original, i)
 			end
+			original[item] = item
+			table.insert(original, item)
 		end
 		return original
 	end

tests/oven/test_lists.lua

@@ -150,5 +150,5 @@
 		prj = project("MyProject")
 		defines { "PROJECT", "DUPLICATE" }
 		cfg = oven.bake(prj, sln, {"Debug"})
-		test.isequal("SOLUTION|DUPLICATE|PROJECT", table.concat(cfg.defines, "|"))
+		test.isequal("SOLUTION|PROJECT|DUPLICATE", table.concat(cfg.defines, "|"))
 	end

tests/project/test_eachconfig.lua

@@ -18,8 +18,11 @@
 		sln = solution("MySolution")
 	end
 
-	local function prepare()
+	local function prepare(buildcfgs)
 		project("MyProject")
+		if buildcfgs then
+			configurations ( buildcfgs )
+		end
 		prj = premake.solution.getproject_ng(sln, 1)
 		for cfg in premake5.project.eachconfig(prj, field) do
 			_p(2,'%s:%s', cfg.buildcfg or "", cfg.platform or "")
@@ -148,3 +151,21 @@
 		]]
 	end
 
+
+--
+-- If there is overlap in the solution and project configuration lists,
+-- the ordering at the project level should be maintained to avoid
+-- unnecessarily dirtying the project file.
+--
+
+	function suite.maintainsProjectOrdering_onSolutionOverlap()
+		configurations { "Debug", "Release" }
+		prepare { "Debug", "Development", "Profile", "Release" }
+		test.capture [[
+		Debug:
+		Development:
+		Profile:
+		Release:
+		]]
+	end
+