From 06ac1870418034c02ecd073a5a85b674a728d892 Mon Sep 17 00:00:00 2001
From: ywang <yw05@forksworld.de>
Date: Sun, 8 Aug 2021 15:36:58 +0200
Subject: Fix newline bug

---
 advtrains/spec/textrender_spec.lua |  2 ++
 advtrains/textrender.lua           | 21 ++++++++++++++++-----
 2 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/advtrains/spec/textrender_spec.lua b/advtrains/spec/textrender_spec.lua
index 063d9ee..f02afec 100644
--- a/advtrains/spec/textrender_spec.lua
+++ b/advtrains/spec/textrender_spec.lua
@@ -1,5 +1,7 @@
 package.path = "../?.lua" .. package.path
 
+-- This unittest file only makes sure that extremely trivial things do not break. It is not intended to be complete
+
 local tr = require("textrender")
 
 describe("string to unicode codepoint sequence converter", function()
diff --git a/advtrains/textrender.lua b/advtrains/textrender.lua
index f23cd3f..de9deac 100644
--- a/advtrains/textrender.lua
+++ b/advtrains/textrender.lua
@@ -146,16 +146,20 @@ end
 local function split_lines(cs, width, height, options)
 	local lines = {}
 	local nlines = options.lines
-	local lwidth = width+1 -- for newline for the first line
+	local lwidth = width+1 -- force newline for the first line
 	local wrap_overflow = options.wrap_overflow
 	local align = options.align
 	local sl = split_into_segments(cs)
 	for i = 1, #sl do
 		seg = sl[i]
 		local seq = seg.seq
+		if not seg.bchar then
+			lwidth = width+1 --force newline
+		end
 		if lwidth + seg.width <= width then
 			local line = lines[#lines]
-			line.width = (line.width or 0) + seg.width
+			lwidth = (line.width or 0) + seg.width
+			line.width = lwidth
 			if seg.bchar then
 				line[#line+1] = seg.bchar
 			end
@@ -168,6 +172,7 @@ local function split_lines(cs, width, height, options)
 			local line = seq
 			line.width = seg.size[#line]
 			lines[#lines+1] = line
+			lwidth = 0
 		else -- now we need to deal with segments longer than the given width
 			if wrap_overflow then
 				-- forcibly break the sequence
@@ -182,7 +187,8 @@ local function split_lines(cs, width, height, options)
 						j = j+1
 					end
 					if l[1] then
-						l.width = st[j-1]-tw
+						lwidth = st[j-1]-tw
+						l.width = lwidth
 						lines[#lines+1] = l
 					end
 					ci = j
@@ -202,6 +208,7 @@ local function split_lines(cs, width, height, options)
 					l.width = l.width + charwidth(seq[i])
 				end
 				lines[#lines+1] = l
+				lwidth = l.width
 			end
 		end
 		if #lines > nlines then
@@ -280,12 +287,15 @@ local function render(str, ...)
 end
 
 if minetest then
+	local tilefmt = "advtrains_hud_bg.png^[resize:128x128^[colorize:#0000ff^(advtrains_hud_bg.png^[resize:128x64)^%s"
+	-- expected: Hello world<one empty line>áéḯṍǘ
+	local sampletext = "Hello world\n\náe"..string.char(0xcc,0x81,0xc3,0xaf,0xcc,0x81,0x6f,0xcc,0x83,0xcc,0x81,0xc7,0x98)
 	minetest.register_node("advtrains:textrender_demo",{
 		description = "Text rendering demo",
-		tiles = {"advtrains_hud_bg.png^[resize:128x128^[colorize:#0000ff^(advtrains_hud_bg.png^[resize:128x64)^"..render("Hello\n\n World", 128, 128, {color="#00ff00"})},
+		tiles = {string.format(tilefmt, render(sampletext, 128, 128, {color="#00ff00"}))},
 		groups = {cracky=3, not_in_creative_inventory=1}
 	})
-	minetest.register_on_mods_loaded(function()
+	minetest.register_on_mods_loaded(function() -- wait until the trainhud module is loaded
 		minetest.register_craft{
 			output = "advtrains:textrender_demo",
 			recipe = {
@@ -299,5 +309,6 @@ end
 
 return {
 	mbstoucs = mbstoucs,
+	render = render,
 	texture_escape = texture_escape,
 }
\ No newline at end of file
-- 
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