vim-patch:8.2.2141: a user command with try/catch may not catch an expression error

Problem:    A user command with try/catch may not catch an expression error.
Solution:   When an expression fails check for following "|". (closes vim/vim#7469)

8143a53c53

Co-authored-by: Bram Moolenaar <Bram@vim.org>

src/nvim/eval.c

@@ -2369,7 +2369,11 @@ int eval0(char *arg, typval_T *rettv, exarg_T *eap, evalarg_T *const evalarg)
     }
 
     // Some of the expression may not have been consumed.  Do not check for
-    // a next command to avoid more errors.
+    // a next command to avoid more errors, unless "|" is following, which
+    // could only be a command separator.
+    if (eap != NULL && skipwhite(p)[0] == '|' && skipwhite(p)[1] != '|') {
+      eap->nextcmd = check_nextcmd(p);
+    }
     return FAIL;
   }
 

test/old/testdir/test_trycatch.vim

@@ -2220,6 +2220,31 @@ func Test_BufEnter_exception()
   %bwipe!
 endfunc
 
+" Test for using try/catch in a user command with a failing expression    {{{1
+func Test_user_command_try_catch()
+  let lines =<< trim END
+      function s:throw() abort
+        throw 'error'
+      endfunction
+
+      command! Execute
+      \   try
+      \ |   let s:x = s:throw()
+      \ | catch
+      \ |   let g:caught = 'caught'
+      \ | endtry
+
+      let g:caught = 'no'
+      Execute
+      call assert_equal('caught', g:caught)
+  END
+  call writefile(lines, 'XtestTryCatch')
+  source XtestTryCatch
+
+  call delete('XtestTryCatch')
+  unlet g:caught
+endfunc
+
 " Test for using throw in a called function with following error    {{{1
 func Test_user_command_throw_in_function_call()
   let lines =<< trim END