From dc84e1e107495e28d29e266705f5486e0a9d14b9 Mon Sep 17 00:00:00 2001
From: Bruce Hill <bitbucket@bruce-hill.com>
Date: Fri, 27 Oct 2017 14:54:47 -0700
Subject: [PATCH] Fixed some questionable newline printing behavior and added
 support for passing in arbitrary tables instead of strings.

---
 diff.lua | 19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)

diff --git a/diff.lua b/diff.lua
index 5404a1b..0c218cc 100644
--- a/diff.lua
+++ b/diff.lua
@@ -63,7 +63,7 @@ local function print_diff(d, options)
                 end
             end
             if not (options and options.context == 0) then
-                io.write((old:gsub("[^\n]*\n?", "  %1")))
+                io.write((old:gsub("([^\n]*)\n?", "  %1\n")))
             end
         else
             -- Changed
@@ -72,18 +72,17 @@ local function print_diff(d, options)
                     print(colors.underscore..colors.bright..colors.red..
                         ("Old line %d-%d:"):format(chunk.old_line, chunk.old_line_end)..colors.reset)
                 end
-                io.write(colors.red..(chunk.old:gsub("[^\n]*\n?", "- %1"))..colors.reset)
+                io.write(colors.red..(chunk.old:gsub("([^\n]*)\n?", "- %1\n"))..colors.reset)
             end
             if #chunk.new > 0 then
                 if line_numbers then
                     print(colors.underscore..colors.bright..colors.green..
                         ("New line %d-%d:"):format(chunk.new_line, chunk.new_line_end)..colors.reset)
                 end
-                io.write(colors.green..(chunk.new:gsub("[^\n]*\n?", "+ %1"))..colors.reset)
+                io.write(colors.green..(chunk.new:gsub("([^\n]*)\n?", "+ %1\n"))..colors.reset)
             end
         end
     end
-    io.write('\n')
 end
 
 local diff_mt = {__index={print=print_diff}}
@@ -95,9 +94,15 @@ local function diff(old, new)
     local insert, concat = table.insert, table.concat
 
     -- Split into lines
-    local A, B = {}, {}
-    for c in old:gmatch("[^\n]*\n?") do insert(A, c) end
-    for c in new:gmatch("[^\n]*\n?") do insert(B, c) end
+    local A, B = old, new
+    if type(A) ~= 'table' then
+        A = {}
+        for c in old:gmatch("[^\n]*\n?") do insert(A, c) end
+    end
+    if type(B) ~= 'table' then
+        B = {}
+        for c in new:gmatch("[^\n]*\n?") do insert(B, c) end
+    end
 
     -- Find the longest common subsequence between A[a_min..a_max] and B[b_min..b_max] (inclusive),
     -- and return (the starting position in a), (the starting position in b), (the length)