Add script to split HG patch sets.

Author: Neopallium

tools/hg_import_split.lua

@@ -0,0 +1,45 @@
+
+local patch = arg[1]
+if not patch then
+	print("run:", arg[0] .. "<hg_patch_set>")
+	return
+end
+
+local prefix, ext = patch:match("^(.*)%.(.*)$")
+
+print("split HG patch set:", prefix .. '.' .. ext)
+
+local input = io.open(patch, "rb")
+
+local part = 0
+local output
+
+local function append_line(line)
+	if output then
+		output:write(line, '\n')
+	end
+end
+
+local function open_next_output()
+	if output then
+		-- close previous patch.
+		output:close()
+		output = nil
+	end
+	part = part + 1
+	local name = string.format("%s_%d.%s", prefix, part, ext)
+	print("Start patch file:", name)
+	output = io.open(name, "w+b")
+end
+
+for line in input:lines() do
+	if line == "# HG changeset patch" then
+		open_next_output()
+	end
+	append_line(line)
+end
+
+if output then
+	output:close()
+end
+