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;
   }