refactor: add xmemcpyz() and use it in place of some xstrlcpy() (#28422)

Problem:  Using xstrlcpy() when the exact length of the string to be
          copied is known is not ideal because it requires adding 1 to
          the length and an unnecessary strlen().
Solution: Add xmemcpyz() and use it in place of such xstrlcpy() calls.

3 files changed, 3 insertions, 3 deletions

diff --git a/src/nvim/os/env.c b/src/nvim/os/env.c
index 8a81f6e928..ed55f4f0eb 100644
--- a/src/nvim/os/env.c
+++ b/src/nvim/os/env.c
@@ -1195,7 +1195,7 @@ bool os_setenv_append_path(const char *fname)
   const char *tail = path_tail_with_sep((char *)fname);
   size_t dirlen = (size_t)(tail - fname);
   assert(tail >= fname && dirlen + 1 < sizeof(os_buf));
-  xstrlcpy(os_buf, fname, dirlen + 1);
+  xmemcpyz(os_buf, fname, dirlen);
   const char *path = os_getenv("PATH");
   const size_t pathlen = path ? strlen(path) : 0;
   const size_t newlen = pathlen + dirlen + 2;
diff --git a/src/nvim/os/fs.c b/src/nvim/os/fs.c
index aa344d786c..2eca906d4e 100644
--- a/src/nvim/os/fs.c
+++ b/src/nvim/os/fs.c
@@ -374,7 +374,7 @@ static bool is_executable_in_path(const char *name, char **abspath)
     char *e = xstrchrnul(p, ENV_SEPCHAR);
 
     // Combine the $PATH segment with `name`.
-    xstrlcpy(buf, p, (size_t)(e - p) + 1);
+    xmemcpyz(buf, p, (size_t)(e - p));
     (void)append_path(buf, name, buf_len);
 
 #ifdef MSWIN
diff --git a/src/nvim/os/stdpaths.c b/src/nvim/os/stdpaths.c
index 187a0e0674..e5bdd56fe6 100644
--- a/src/nvim/os/stdpaths.c
+++ b/src/nvim/os/stdpaths.c
@@ -198,7 +198,7 @@ char *get_xdg_home(const XDGVarType idx)
   assert(appname_len < (IOSIZE - sizeof("-data")));
 
   if (dir) {
-    xstrlcpy(IObuff, appname, appname_len + 1);
+    xmemcpyz(IObuff, appname, appname_len);
 #if defined(MSWIN)
     if (idx == kXDGDataHome || idx == kXDGStateHome) {
       xstrlcat(IObuff, "-data", IOSIZE);