patch 8.2.3293: finding completions may cause an endless loop

Problem:    Finding completions may cause an endless loop.
Solution:   Use a better way to check coming back where the search started.
            (Andy Gozas, closes #8672, closes #8671)
diff --git a/src/testdir/Make_all.mak b/src/testdir/Make_all.mak
index 6feeecd..3c54087 100644
--- a/src/testdir/Make_all.mak
+++ b/src/testdir/Make_all.mak
@@ -162,6 +162,7 @@
 	test_increment_dbcs \
 	test_indent \
 	test_ins_complete \
+	test_ins_complete_no_halt \
 	test_interrupt \
 	test_job_fails \
 	test_join \
@@ -405,6 +406,7 @@
 	test_increment_dbcs.res \
 	test_indent.res \
 	test_ins_complete.res \
+	test_ins_complete_no_halt.res \
 	test_interrupt.res \
 	test_job_fails.res \
 	test_join.res \
diff --git a/src/testdir/test_ins_complete_no_halt.vim b/src/testdir/test_ins_complete_no_halt.vim
new file mode 100644
index 0000000..e12925d
--- /dev/null
+++ b/src/testdir/test_ins_complete_no_halt.vim
@@ -0,0 +1,51 @@
+" Test insert mode completion does not get stuck when looping around.
+" In a separate file to avoid the settings to leak to other test cases.
+
+set complete+=kspell
+set completeopt+=menu
+set completeopt+=menuone
+set completeopt+=noselect
+set completeopt+=noinsert
+let g:autocompletion = v:true
+
+func Test_ins_complete_no_halt()
+  function! OpenCompletion()
+    if pumvisible() && (g:autocompletion == v:true)
+      call feedkeys("\<C-e>\<C-n>", "i")
+      return
+    endif
+    if ((v:char >= 'a' && v:char <= 'z') || (v:char >= 'A' && v:char <= 'Z')) && (g:autocompletion == v:true)
+      call feedkeys("\<C-n>", "i")
+      redraw
+    endif
+  endfunction
+
+  autocmd InsertCharPre * noautocmd call OpenCompletion()
+
+  setlocal spell! spelllang=en_us
+
+  call feedkeys("iauto-complete-halt-test test test test test test test test test test test test test test test test test test test\<C-c>", "tx!")
+  call assert_equal(["auto-complete-halt-test test test test test test test test test test test test test test test test test test test"], getline(1, "$"))
+endfunc
+
+func Test_auto_complete_backwards_no_halt()
+  function! OpenCompletion()
+    if pumvisible() && (g:autocompletion == v:true)
+      call feedkeys("\<C-e>\<C-p>", "i")
+      return
+    endif
+    if ((v:char >= 'a' && v:char <= 'z') || (v:char >= 'A' && v:char <= 'Z')) && (g:autocompletion == v:true)
+      call feedkeys("\<C-p>", "i")
+      redraw
+    endif
+  endfunction
+
+  autocmd InsertCharPre * noautocmd call OpenCompletion()
+
+  setlocal spell! spelllang=en_us
+
+  call feedkeys("iauto-complete-halt-test test test test test test test test test test test test test test test test test test test\<C-c>", "tx!")
+  call assert_equal(["auto-complete-halt-test test test test test test test test test test test test test test test test test test test"], getline(1, "$"))
+endfunc
+
+" vim: shiftwidth=2 sts=2 expandtab