vim-patch:9.0.1508: catch does not work when lines are joined with a newline

Problem:    Catch does not work when lines are joined with a newline.
Solution:   Set "nextcmd" appropriately. (closes vim/vim#12348)

f2588b6fc9

src/nvim/eval.c

@@ -2368,11 +2368,14 @@ 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
+    if (eap != NULL && p != NULL) {
-    // a next command to avoid more errors, unless "|" is following, which
+      // Some of the expression may not have been consumed.
-    // could only be a command separator.
+      // Only execute a next command if it cannot be a "||" operator.
-    if (eap != NULL && skipwhite(p)[0] == '|' && skipwhite(p)[1] != '|') {
+      // The next command may be "catch".
-      eap->nextcmd = check_nextcmd(p);
+      char *nextcmd = check_nextcmd(p);
+      if (nextcmd != NULL && *nextcmd != '|') {
+        eap->nextcmd = nextcmd;
+      }
     }
     return FAIL;
   }

test/old/testdir/test_trycatch.vim

@@ -2220,6 +2220,36 @@ func Test_BufEnter_exception()
   %bwipe!
 endfunc
 
+" Test for using try/catch when lines are joined by "|" or "\n"           {{{1
+func Test_try_catch_nextcmd()
+  func Throw()
+    throw "Failure"
+  endfunc
+
+  let lines =<< trim END
+    try
+      let s:x = Throw()
+    catch
+      let g:caught = 1
+    endtry
+  END
+
+  let g:caught = 0
+  call execute(lines)
+  call assert_equal(1, g:caught)
+
+  let g:caught = 0
+  call execute(join(lines, '|'))
+  call assert_equal(1, g:caught)
+
+  let g:caught = 0
+  call execute(join(lines, "\n"))
+  call assert_equal(1, g:caught)
+
+  unlet g:caught
+  delfunc Throw
+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