vim-patch:9.1.0313: Crash when using heredoc with comment in command block

Problem:  Crash when using heredoc with comment in command block.
Solution: Handle a newline more like the end of the line, fix coverity
          warning (zeertzjq).

closes: vim/vim#14535

https://github.com/vim/vim/commit/1f5175d9af3d3f37e19f23e0e6f84caec47390f2

2 files changed, 10 insertions, 23 deletions

diff --git a/src/nvim/charset.c b/src/nvim/charset.c
index 59932b2eb0..c611d4cfd6 100644
--- a/src/nvim/charset.c
+++ b/src/nvim/charset.c
@@ -1045,20 +1045,6 @@ char *skiptowhite(const char *p)
   return (char *)p;
 }
 
-/// Skip over text until ' ' or '\t' or newline or NUL
-///
-/// @param[in]  p  Text to skip over.
-///
-/// @return Pointer to the next whitespace or newline or NUL character.
-char *skiptowhite_or_nl(const char *p)
-  FUNC_ATTR_NONNULL_ALL FUNC_ATTR_PURE
-{
-  while (*p != ' ' && *p != '\t' && *p != NL && *p != NUL) {
-    p++;
-  }
-  return (char *)p;
-}
-
 /// skiptowhite_esc: Like skiptowhite(), but also skip escaped chars
 ///
 /// @param p
diff --git a/src/nvim/eval/vars.c b/src/nvim/eval/vars.c
index 70ecb76deb..37199cd95d 100644
--- a/src/nvim/eval/vars.c
+++ b/src/nvim/eval/vars.c
@@ -179,8 +179,15 @@ list_T *heredoc_get(exarg_T *eap, char *cmd, bool script_get)
   int text_indent_len = 0;
   char *text_indent = NULL;
   char dot[] = ".";
+  bool heredoc_in_string = false;
+  char *line_arg = NULL;
+  char *nl_ptr = vim_strchr(cmd, '\n');
 
-  if (eap->ea_getline == NULL && vim_strchr(cmd, '\n') == NULL) {
+  if (nl_ptr != NULL) {
+    heredoc_in_string = true;
+    line_arg = nl_ptr + 1;
+    *nl_ptr = NUL;
+  } else if (eap->ea_getline == NULL) {
     emsg(_(e_cannot_use_heredoc_here));
     return NULL;
   }
@@ -217,17 +224,11 @@ list_T *heredoc_get(exarg_T *eap, char *cmd, bool script_get)
   }
 
   const char comment_char = '"';
-  bool heredoc_in_string = false;
-  char *line_arg = NULL;
   // The marker is the next word.
   if (*cmd != NUL && *cmd != comment_char) {
     marker = skipwhite(cmd);
-    char *p = skiptowhite_or_nl(marker);
-    if (*p == NL) {
-      // heredoc in a string
-      line_arg = p + 1;
-      heredoc_in_string = true;
-    } else if (*skipwhite(p) != NUL && *skipwhite(p) != comment_char) {
+    char *p = skiptowhite(marker);
+    if (*skipwhite(p) != NUL && *skipwhite(p) != comment_char) {
       semsg(_(e_trailing_arg), p);
       return NULL;
     }