fs.c: fix is_executable_ext()

- Corresponds to the case where pathext contains a zero-length
  extension.
- Remove unnecessary break statements.
- Fix function attributes.

1 files changed, 9 insertions, 11 deletions

diff --git a/src/nvim/os/fs.c b/src/nvim/os/fs.c
index 2621d9da74..91ed639a1b 100644
--- a/src/nvim/os/fs.c
+++ b/src/nvim/os/fs.c
@@ -301,7 +301,7 @@ static bool is_executable(const char *name, char_u **abspath)
 /// - if the file extension is in $PATHEXT and `name` is executable
 /// - if the result of any $PATHEXT extension appended to `name` is executable
 static bool is_executable_ext(char *name, char_u **abspath)
-  FUNC_ATTR_NONNULL_ARG(1, 2)
+  FUNC_ATTR_NONNULL_ARG(1)
 {
   const bool is_unix_shell = strstr((char *)path_tail(p_sh), "sh") != NULL;
   char *nameext = strrchr(name, '.');
@@ -325,17 +325,15 @@ static bool is_executable_ext(char *name, char_u **abspath)
 
     const char *ext_end = xstrchrnul(ext, ENV_SEPCHAR);
     size_t ext_len = (size_t)(ext_end - ext);
-    STRLCPY(buf_end, ext, ext_len + 1);
-    bool in_pathext = nameext_len == ext_len
-      && 0 == mb_strnicmp((char_u *)nameext, (char_u *)ext, ext_len);
-
-    if (((in_pathext || is_unix_shell) && is_executable(name, abspath))
-        || is_executable(os_buf, abspath)) {
-      return true;
-    }
+    if (ext_len != 0) {
+      STRLCPY(buf_end, ext, ext_len + 1);
+      bool in_pathext = nameext_len == ext_len
+        && 0 == mb_strnicmp((char_u *)nameext, (char_u *)ext, ext_len);
 
-    if (*ext_end != ENV_SEPCHAR) {
-      break;
+      if (((in_pathext || is_unix_shell) && is_executable(name, abspath))
+          || is_executable(os_buf, abspath)) {
+        return true;
+      }
     }
     ext = ext_end;
   }