patch 8.2.4949: Vim9: some code not covered by tests

Problem:    Vim9: some code not covered by tests.
Solution:   Add a few more test cases.  Fix double error message.

src/testdir/test_vim9_expr.vim

@@ -545,6 +545,12 @@ def Test_expr3_fails()
       endif
   END
   v9.CheckDefAndScriptFailure(lines, ['E1012:', 'E1135: Using a String as a Bool'], 1)
+
+  lines =<< trim END
+      var s = 'asdf'
+      echo true && s
+  END
+  v9.CheckDefAndScriptFailure(lines, ['E1012: Type mismatch; expected bool but got string', 'E1135: Using a String as a Bool: "asdf"'])
 enddef
 
 " global variables to use for tests with the "any" type
@@ -3377,6 +3383,18 @@ def Test_expr8_parens()
 
   v9.CheckDefAndScriptFailure(['echo ('], ['E1097: Line incomplete', 'E15: Invalid expression: "("'])
   v9.CheckDefAndScriptFailure(['echo (123]'], "E110: Missing ')'", 1)
+
+  # this uses up the ppconst stack
+  lines =<< eval trim END
+    vim9script
+    def F()
+      g:result = 1 + {repeat('(1 + ', 51)}1{repeat(')', 51)}
+    enddef
+    F()
+  END
+  v9.CheckScriptSuccess(lines)
+  assert_equal(g:result, 53)
+  unlet g:result
 enddef
 
 def Test_expr8_negate_add()
@@ -3623,6 +3641,18 @@ def Test_expr8_method_call()
     RetVoid()->byteidx(3)
   END
   v9.CheckDefExecFailure(lines, 'E1013:')
+
+  lines =<< trim END
+      const SetList = [function('len')]
+      echo 'xx'->SetList[x]()
+  END
+  v9.CheckDefFailure(lines, 'E1001: Variable not found: x')
+
+  lines =<< trim END
+      const SetList = [function('len')]
+      echo 'xx'->SetList[0]x()
+  END
+  v9.CheckDefFailure(lines, 'E15: Invalid expression: "->SetList[0]x()"')
 enddef
 
 def Test_expr8_method_call_linebreak()
@@ -3785,6 +3815,8 @@ func Test_expr8_fails()
 
   call v9.CheckDefExecFailure(["{['a']: 1->len()"], 'E723:', 2)
   call v9.CheckScriptFailure(['vim9script', "{['a']: 1->len()"], 'E722:', 2)
+
+  call v9.CheckDefFailure(['echo #{}'], 'E1170:')
 endfunc
 
 let g:Funcrefs = [function('add')]

src/version.c

@@ -746,6 +746,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    4949,
 /**/
     4948,
 /**/

src/vim9expr.c

@@ -1899,6 +1899,7 @@ compile_subscript(
 		{
 		    int fail;
 		    int save_len = cctx->ctx_ufunc->uf_lines.ga_len;
+		    int	prev_did_emsg = did_emsg;
 
 		    *paren = NUL;
 
@@ -1916,7 +1917,8 @@ compile_subscript(
 
 		    if (fail)
 		    {
-			semsg(_(e_invalid_expression_str), pstart);
+			if (did_emsg == prev_did_emsg)
+			    semsg(_(e_invalid_expression_str), pstart);
 			return FAIL;
 		    }
 		}