input: Escape utf8 sequences that contain CSI/K_SPECIAL

src/nvim/os/input.c

@@ -148,22 +148,34 @@ size_t input_enqueue(String keys)
     uint8_t buf[6] = {0};
     unsigned int new_size = trans_special((uint8_t **)&ptr, buf, true);
 
-    if (!new_size) {
-      if (*ptr == '<') {
-        // Invalid key sequence, skip until the next '>' or until *end
-        do {
-          ptr++;
-        } while (ptr < end && *ptr != '>');
-        ptr++;
-        continue;
-      }
-      // copy the character unmodified
-      *buf = (uint8_t)*ptr++;
-      new_size = 1;
+    if (new_size) {
+      new_size = handle_mouse_event(&ptr, buf, new_size);
+      rbuffer_write(input_buffer, (char *)buf, new_size);
+      continue;
     }
 
-    new_size = handle_mouse_event(&ptr, buf, new_size);
-    rbuffer_write(input_buffer, (char *)buf, new_size);
+    if (*ptr == '<') {
+      // Invalid key sequence, skip until the next '>' or until *end
+      do {
+        ptr++;
+      } while (ptr < end && *ptr != '>');
+      ptr++;
+      continue;
+    }
+
+    // copy the character, escaping CSI and K_SPECIAL
+    if ((uint8_t)*ptr == CSI) {
+      rbuffer_write(input_buffer, (char *)&(uint8_t){K_SPECIAL}, 1);
+      rbuffer_write(input_buffer, (char *)&(uint8_t){KS_EXTRA}, 1);
+      rbuffer_write(input_buffer, (char *)&(uint8_t){KE_CSI}, 1);
+    } else if ((uint8_t)*ptr == K_SPECIAL) {
+      rbuffer_write(input_buffer, (char *)&(uint8_t){K_SPECIAL}, 1);
+      rbuffer_write(input_buffer, (char *)&(uint8_t){KS_SPECIAL}, 1);
+      rbuffer_write(input_buffer, (char *)&(uint8_t){KE_FILLER}, 1);
+    } else {
+      rbuffer_write(input_buffer, ptr, 1);
+    }
+    ptr++;
   }
 
   size_t rv = (size_t)(ptr - keys.data);

test/functional/legacy/mapping_spec.lua

@@ -16,7 +16,7 @@ describe('mapping', function()
 
     -- Abbreviations with р (0x80) should work.
     execute('inoreab чкпр   vim')
-    feed('GAчкпр <cr><esc>')
+    feed('GAчкпр <esc>')
 
     -- langmap should not get remapped in insert mode.
     execute('inoremap { FAIL_ilangmap')
@@ -27,10 +27,11 @@ describe('mapping', function()
     execute('inoremap <expr> { "FAIL_iexplangmap"')
     feed('o+<esc>')
 
+
     -- Assert buffer contents.
     expect([[
       test starts here:
-      vim
+      vim 
       +
       +]])
   end)

test/functional/ui/input_spec.lua

@@ -1,6 +1,7 @@
 local helpers = require('test.functional.helpers')
 local clear, execute, nvim = helpers.clear, helpers.execute, helpers.nvim
 local feed, next_message, eq = helpers.feed, helpers.next_message, helpers.eq
+local expect = helpers.expect
 
 describe('mappings', function()
   local cid
@@ -38,3 +39,10 @@ describe('mappings', function()
     check_mapping('<a-s-c-up>', '<c-s-a-up>')
   end)
 end)
+
+describe('input utf sequences that contain CSI/K_SPECIAL', function()
+  it('ok', function()
+    feed('i…<esc>')
+    expect('…')
+  end)
+end)