vim-patch:8.2.4073: Coverity warns for using NULL pointer

Problem:    Coverity warns for using NULL pointer.
Solution:   Bail out when running out of memory. Check for running over end of
            a string.

https://github.com/vim/vim/commit/54598066ca4cfaf0761aedf47e4ba9844674791e

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

1 files changed, 7 insertions, 6 deletions

diff --git a/src/nvim/eval/userfunc.c b/src/nvim/eval/userfunc.c
index fbb5e8d10c..11ed537210 100644
--- a/src/nvim/eval/userfunc.c
+++ b/src/nvim/eval/userfunc.c
@@ -467,12 +467,10 @@ char *deref_func_name(const char *name, int *lenp, partial_T **const partialp, b
 /// @param name function name
 void emsg_funcname(const char *errmsg, const char *name)
 {
-  char *p;
+  char *p = (char *)name;
 
-  if ((uint8_t)(*name) == K_SPECIAL) {
+  if ((uint8_t)name[0] == K_SPECIAL && name[1] != NUL && name[2] != NUL) {
     p = concat_str("<SNR>", name + 3);
-  } else {
-    p = (char *)name;
   }
 
   semsg(_(errmsg), p);
@@ -1863,8 +1861,7 @@ char *trans_function_name(char **pp, bool skip, int flags, funcdict_T *fdp, part
 
   // Check for hard coded <SNR>: already translated function ID (from a user
   // command).
-  if ((unsigned char)(*pp)[0] == K_SPECIAL && (unsigned char)(*pp)[1] == KS_EXTRA
-      && (*pp)[2] == KE_SNR) {
+  if ((uint8_t)(*pp)[0] == K_SPECIAL && (uint8_t)(*pp)[1] == KS_EXTRA && (*pp)[2] == KE_SNR) {
     *pp += 3;
     len = get_id_len((const char **)pp) + 3;
     return xmemdupz(start, (size_t)len);
@@ -2232,6 +2229,10 @@ void ex_function(exarg_T *eap)
     eap->skip = true;
   }
 
+  if (name == NULL) {
+    goto ret_free;
+  }
+
   // An error in a function call during evaluation of an expression in magic
   // braces should not cause the function not to be defined.
   saved_did_emsg = did_emsg;