fix(eval): cherry-pick emsg changes from v8.1.0736

v8.1.0736 made some changes for making some emsgs more specific.
Includes the change for Test_lambda_fails() in test_lambda.vim.
Adjust relevant functionaltests to expect the new emsgs.

This patch has been fully ported in my Blob port PR, but it hasn't been
merged yet, so just use what we need from it for now.

Required for v8.1.1821.

1 files changed, 9 insertions, 3 deletions

diff --git a/src/nvim/eval.c b/src/nvim/eval.c
index 789936fdff..5634eafdf2 100644
--- a/src/nvim/eval.c
+++ b/src/nvim/eval.c
@@ -3162,6 +3162,8 @@ int eval0(char_u *arg, typval_T *rettv, char_u **nextcmd, int evaluate)
 {
   int ret;
   char_u      *p;
+  const int did_emsg_before = did_emsg;
+  const int called_emsg_before = called_emsg;
 
   p = skipwhite(arg);
   ret = eval1(&p, rettv, evaluate);
@@ -3171,8 +3173,10 @@ int eval0(char_u *arg, typval_T *rettv, char_u **nextcmd, int evaluate)
     }
     // Report the invalid expression unless the expression evaluation has
     // been cancelled due to an aborting error, an interrupt, or an
-    // exception.
-    if (!aborting()) {
+    // exception, or we already gave a more specific error.
+    // Also check called_emsg for when using assert_fails().
+    if (!aborting() && did_emsg == did_emsg_before
+        && called_emsg == called_emsg_before) {
       emsgf(_(e_invexpr2), arg);
     }
     ret = FAIL;
@@ -9275,6 +9279,7 @@ void ex_echo(exarg_T *eap)
   bool atstart = true;
   bool need_clear = true;
   const int did_emsg_before = did_emsg;
+  const int called_emsg_before = called_emsg;
 
   if (eap->skip)
     ++emsg_skip;
@@ -9289,7 +9294,8 @@ void ex_echo(exarg_T *eap)
         // Report the invalid expression unless the expression evaluation
         // has been cancelled due to an aborting error, an interrupt, or an
         // exception.
-        if (!aborting() && did_emsg == did_emsg_before) {
+        if (!aborting() && did_emsg == did_emsg_before
+            && called_emsg == called_emsg_before) {
           EMSG2(_(e_invexpr2), p);
         }
         need_clr_eos = false;