2 files changed, 59 insertions, 0 deletions
diff --git a/test/unit/search_spec.lua b/test/unit/search_spec.lua
index 3c2d485e0e..ef5a0cb831 100644
--- a/test/unit/search_spec.lua
+++ b/test/unit/search_spec.lua
@@ -5,6 +5,8 @@ local to_cstr = helpers.to_cstr
 local eq      = helpers.eq
 
 local search = helpers.cimport("./src/nvim/search.h")
+local globals = helpers.cimport('./src/nvim/globals.h')
+local ffi = helpers.ffi
 
 itp('pat_has_uppercase', function()
   -- works on empty string
@@ -31,3 +33,25 @@ itp('pat_has_uppercase', function()
   eq(false, search.pat_has_uppercase(to_cstr("aa\\%Ab")))
   eq(true, search.pat_has_uppercase(to_cstr("aab\\%AU")))
 end)
+
+describe('search_regcomp', function()
+  local search_regcomp = function(pat, pat_save, pat_use, options )
+    local regmatch = ffi.new("regmmatch_T")
+    local fail = search.search_regcomp(to_cstr(pat), pat_save, pat_use, options, regmatch)
+    return fail, regmatch
+  end
+
+  local get_search_pat = function()
+    return helpers.internalize(search.get_search_pat())
+  end
+
+  itp("accepts regexp pattern with invalid utf", function()
+    --crafted to call reverse_text with invalid utf
+    globals.curwin.w_onebuf_opt.wo_rl = 1
+    globals.curwin.w_onebuf_opt.wo_rlc = to_cstr('s')
+    globals.cmdmod.keeppatterns = 1
+    local fail = search_regcomp("a\192", 0,0,0)
+    eq(1, fail)
+    eq("\192a", get_search_pat())
+  end)
+end)
diff --git a/test/unit/strings_spec.lua b/test/unit/strings_spec.lua
index e085ac749d..b2c839f25c 100644
--- a/test/unit/strings_spec.lua
+++ b/test/unit/strings_spec.lua
@@ -150,3 +150,38 @@ describe('strcase_save()' , function()
     eq("a", strcase_save("\xc1\x81", false))
   end)
 end)
+
+describe("reverse_text", function()
+  local reverse_text = function(str)
+    return helpers.internalize(strings.reverse_text(to_cstr(str)))
+  end
+
+  itp("handles empty string", function()
+    eq("", reverse_text(""))
+  end)
+
+  itp("handles simple cases", function()
+    eq("a", reverse_text("a"))
+    eq("ba", reverse_text("ab"))
+  end)
+
+  itp("handles multibyte characters", function()
+    eq("bα", reverse_text("αb"))
+    eq("Yötön yö", reverse_text("öy nötöY"))
+  end)
+
+  itp("handles combining chars", function()
+    local utf8_COMBINING_RING_ABOVE = "\204\138"
+    local utf8_COMBINING_RING_BELOW = "\204\165"
+    eq("bba" .. utf8_COMBINING_RING_ABOVE .. utf8_COMBINING_RING_BELOW .. "aa",
+       reverse_text("aaa" .. utf8_COMBINING_RING_ABOVE .. utf8_COMBINING_RING_BELOW .. "bb"))
+  end)
+
+  itp("treats invalid utf as separate characters", function()
+    eq("\192ba", reverse_text("ab\192"))
+  end)
+
+  itp("treats an incomplete utf continuation sequence as valid", function()
+    eq("\194ba", reverse_text("ab\194"))
+  end)
+end)