#
#
# patch "std_hooks.lua"
#  from [fc9105dfa61de34c02ce6453f6ac616f581d03f5]
#    to [6ca29b67a6913342668b4cfa2464a37654615280]
#
============================================================
--- std_hooks.lua	fc9105dfa61de34c02ce6453f6ac616f581d03f5
+++ std_hooks.lua	6ca29b67a6913342668b4cfa2464a37654615280
@@ -476,49 +476,90 @@ mergers.rcsmerge = {
    wanted = function () return os.getenv("MTN_RCSMERGE") ~= nil end
 }
 
-mergers.diffutils = {
-   cmd = function (tbl)
-      local ret = execute(
-          "diff3",
-          "--merge",
-          "--label", string.format("%s [left]",     tbl.left_path ),
-          "--label", string.format("%s [ancestor]", tbl.anc_path  ),
-          "--label", string.format("%s [right]",    tbl.right_path),
-          tbl.lfile,
-          tbl.afile,
-          tbl.rfile
-      )
-      if (ret == 2) then
-         io.write(gettext("Error running GNU diffutils 3-way difference tool 'diff3'\n"))
-         return false
-      end
-      local ret = execute(
-          "sdiff",
-          "--diff-program=diff",
-          "--suppress-common-lines",
-          "--minimal",
-          "--output", tbl.outfile,
-          tbl.lfile,
-          tbl.rfile
-      )
-      if (ret == 2) then
-         io.write(gettext("Error running GNU diffutils 2-two merging tool 'sdiff'\n"))
-         return false
-      end
-      return tbl.outfile
-   end,
-   available =
-      function ()
-          return program_exists_in_path("diff3") and
-                 program_exists_in_path("sdiff") and
-                 program_exists_in_path("diff");
-      end,
-   wanted =
-      function ()
-           return true
-      end
-}
+--  GNU diffutils based merging
+mergers.diffutils_new = {
+    --  merge procedure execution
+    cmd = function (tbl)
+        if os.getenv("MTN_MERGE_DIFFUTILS") == "partial" then
+            --  partial batch/non-modal 3-way merge "resolution":
+            --  simply merge content with help of conflict markers
+            io.write("performing 3-way merge, adding conflict markers\n")
+            local ret = execute(
+                "sh", "-c",
+                "diff3 " ..
+                "--merge " ..
+                "--show-overlap " ..
+                "--label '" .. string.format("%s [left]",     tbl.left_path ) .. "' " ..
+                "--label '" .. string.format("%s [ancestor]", tbl.anc_path  ) .. "' " ..
+                "--label '" .. string.format("%s [right]",    tbl.right_path) .. "' " ..
+                string.gsub(tbl.lfile, "\\", "/") .. " " ..
+                string.gsub(tbl.afile, "\\", "/") .. " " ..
+                string.gsub(tbl.rfile, "\\", "/") .. " " ..
+                ">" .. string.gsub(tbl.outfile, "\\", "/")
+            )
+            if ret == 2 then
+                io.write(gettext("Error running GNU diffutils 3-way difference/merge tool 'diff3'\n"))
+                return false
+            end
+            return tbl.outfile
+        else
+            --  real interactive/modal 3/2-way merge resolution:
+            --  display 3-way merge conflict and perform 2-way merge resolution
 
+            --  display 3-way merge conflict (batch)
+            io.write("\n")
+            io.write("---- CONFLICT SUMMARY ------------------------------------------------\n")
+            local ret = execute(
+                "diff3",
+                "--merge",
+                "--show-overlap",
+                "--label", string.format("%s [left]",     tbl.left_path ),
+                "--label", string.format("%s [ancestor]", tbl.anc_path  ),
+                "--label", string.format("%s [right]",    tbl.right_path),
+                string.gsub(tbl.lfile, "\\", "/") .. "",
+                string.gsub(tbl.afile, "\\", "/") .. "",
+                string.gsub(tbl.rfile, "\\", "/") .. ""
+            )
+            if ret == 2 then
+                io.write(gettext("Error running GNU diffutils 3-way difference/merge tool 'diff3'\n"))
+                return false
+            end
+
+            --  perform 2-way merge resolution (interactive)
+            io.write("\n")
+            io.write("---- CONFLICT RESOLUTION ---------------------------------------------\n")
+            local ret = execute(
+                "sdiff",
+                "--diff-program=diff",
+                "--suppress-common-lines",
+                "--minimal",
+                "--output", string.gsub(tbl.outfile, "\\", "/"),
+                string.gsub(tbl.lfile, "\\", "/") .. "",
+                string.gsub(tbl.rfile, "\\", "/") .. ""
+            )
+            if ret == 2 then
+                io.write(gettext("Error running GNU diffutils 2-way merging tool 'sdiff'\n"))
+                return false
+            end
+            return tbl.outfile
+        end
+    end,
+
+    --  merge procedure availability check
+    available = function ()
+        --  make sure the GNU diffutils tools are available
+        return program_exists_in_path("diff3") and
+               program_exists_in_path("sdiff") and
+               program_exists_in_path("diff");
+    end,
+
+    --  merge procedure request check
+    wanted = function ()
+        --  assume it is requested (if it is available at all)
+        return true
+    end
+}   
+
 mergers.emacs = {
    cmd = function (tbl)
       local emacs