*: Partial string handling refactoring

Main points:

- Replace `char_u` with `char` in some cases.
- Remove `str[len] = NUL` hack in some cases when `str` may be considered
  `const`.

1 files changed, 7 insertions, 8 deletions

diff --git a/src/nvim/quickfix.c b/src/nvim/quickfix.c
index c40403e3f6..3b86662f05 100644
--- a/src/nvim/quickfix.c
+++ b/src/nvim/quickfix.c
@@ -2068,21 +2068,20 @@ void qf_list(exarg_T *eap)
       if (qfp->qf_lnum == 0) {
         IObuff[0] = NUL;
       } else if (qfp->qf_col == 0) {
-        vim_snprintf((char *)IObuff, IOSIZE, ":%" PRId64,
-                     (int64_t)qfp->qf_lnum);
+        vim_snprintf((char *)IObuff, IOSIZE, ":%" PRIdLINENR, qfp->qf_lnum);
       } else {
-        vim_snprintf((char *)IObuff, IOSIZE, ":%" PRId64 " col %d",
-                     (int64_t)qfp->qf_lnum, qfp->qf_col);
+        vim_snprintf((char *)IObuff, IOSIZE, ":%" PRIdLINENR " col %d",
+                     qfp->qf_lnum, qfp->qf_col);
       }
       vim_snprintf((char *)IObuff + STRLEN(IObuff), IOSIZE, "%s:",
                    (char *)qf_types(qfp->qf_type, qfp->qf_nr));
-      msg_puts_attr(IObuff, hl_attr(HLF_N));
+      msg_puts_attr((const char *)IObuff, hl_attr(HLF_N));
       if (qfp->qf_pattern != NULL) {
         qf_fmt_text(qfp->qf_pattern, IObuff, IOSIZE);
-        STRCAT(IObuff, ":");
-        msg_puts(IObuff);
+        STRNCAT(IObuff, ":", IOSIZE);
+        msg_puts((const char *)IObuff);
       }
-      msg_puts((char_u *)" ");
+      msg_puts(" ");
 
       /* Remove newlines and leading whitespace from the text.  For an
        * unrecognized line keep the indent, the compiler may mark a word