Fix warnings: fold.c: get_foldtext(): Np dereference: FP.

Problem    : Dereference of null pointer @ 1701.
Diagnostic : False positive.
Rationale  : Comparison `last_wp != wp` just after initializing
             `last_wp` to NULL makes the compiler think `wp` can be
             null. Error appears then on codepath assuming comparison is
             false (i.e. `wp` is null).
Resolution : Change order of OR clauses.
             That seems not to give motives for the analyzer to check
             the `wp` null path and removes the warning.
             But potential null dereference is still there, so we add
             the nonnull annotation to `wp` parameter.

1 files changed, 5 insertions, 3 deletions

diff --git a/src/nvim/fold.c b/src/nvim/fold.c
index 95f1e054b9..6014dbfd15 100644
--- a/src/nvim/fold.c
+++ b/src/nvim/fold.c
@@ -22,6 +22,7 @@
 #include "nvim/diff.h"
 #include "nvim/eval.h"
 #include "nvim/ex_docmd.h"
+#include "nvim/func_attr.h"
 #include "nvim/indent.h"
 #include "nvim/mark.h"
 #include "nvim/memline.h"
@@ -1680,7 +1681,9 @@ static void foldDelMarker(linenr_T lnum, char_u *marker, int markerlen)
  * When 'foldtext' isn't set puts the result in "buf[51]".  Otherwise the
  * result is in allocated memory.
  */
-char_u *get_foldtext(win_T *wp, linenr_T lnum, linenr_T lnume, foldinfo_T *foldinfo, char_u *buf)
+char_u *get_foldtext(win_T *wp, linenr_T lnum, linenr_T lnume,
+                     foldinfo_T *foldinfo, char_u *buf)
+  FUNC_ATTR_NONNULL_ARG(1)
 {
   char_u      *text = NULL;
   /* an error occurred when evaluating 'fdt' setting */
@@ -1689,8 +1692,7 @@ char_u *get_foldtext(win_T *wp, linenr_T lnum, linenr_T lnume, foldinfo_T *foldi
   static win_T    *last_wp = NULL;
   static linenr_T last_lnum = 0;
 
-  if (last_wp != wp || last_wp == NULL
-      || last_lnum > lnum || last_lnum == 0)
+  if (last_wp == NULL || last_wp != wp || last_lnum > lnum || last_lnum == 0)
     /* window changed, try evaluating foldtext setting once again */
     got_fdt_error = FALSE;