Fixed a bug when including the same project in multiple workspaces, when using the includeexternal API. Based on discussion in #122

src/base/_foundation.lua

@@ -221,6 +221,20 @@
 	end
 
 
+--
+-- Finds the correct premake script filename to be run.
+--
+-- @param fname
+--    The filename of the script to run.
+-- @return
+--    The correct location and filename of the script to run.
+--
+
+	function premake.findProjectScript(fname)
+		return os.locate(fname, fname .. ".lua", path.join(fname, "premake5.lua"), path.join(fname, "premake4.lua"))
+	end
+
+
 ---
 -- "Immediate If" - returns one of the two values depending on the value
 -- of the provided condition. Note that both the true and false expressions

src/base/api.lua

@@ -76,12 +76,15 @@
 ---
 -- Register a general-purpose includeExternal() call which works just like
 -- include(), but marks any containers created while evaluating the included
--- scripts as external.
+-- scripts as external. It also, loads the file regardless of how many times
+-- it has been loaded already.
 ---
 
 	function includeexternal(fname)
+		local fullPath = premake.findProjectScript(fname)
 		api._isIncludingExternal = true
-		include(fname)
+		fname = fullPath or fname
+		dofile(fname)
 		api._isIncludingExternal = nil
 	end
 

src/base/globals.lua

@@ -48,7 +48,7 @@
 	io._includedFiles = {}
 
 	function include(fname)
-		local fullPath = os.locate(fname, fname .. ".lua", path.join(fname, "premake5.lua"), path.join(fname, "premake4.lua"))
+		local fullPath = premake.findProjectScript(fname)
 		fname = fullPath or fname
 		if not io._includedFiles[fname] then
 			io._includedFiles[fname] = true

tests/base/test_include.lua

@@ -46,3 +46,21 @@
 		include (_TESTS_DIR .. "/../tests/folder/premake5.lua")
 		test.isequal("ok", premake.captured())
 	end
+
+	function suite.includeexternal_runs()
+		includeexternal (_TESTS_DIR .. "/folder/premake5.lua")
+		test.isequal("ok", premake.captured())
+	end
+
+	function suite.includeexternal_runsAfterInclude()
+		include (_TESTS_DIR .. "/folder/premake5.lua")
+		includeexternal (_TESTS_DIR .. "/folder/premake5.lua")
+		test.isequal("okok", premake.captured())
+	end
+
+	function suite.includeexternal_runsTwiceAfterInclude()
+		include (_TESTS_DIR .. "/folder/premake5.lua")
+		includeexternal (_TESTS_DIR .. "/folder/premake5.lua")
+		includeexternal (_TESTS_DIR .. "/folder/premake5.lua")
+		test.isequal("okokok", premake.captured())
+	end