Merge from origin/emacs-27

59e768d64a Fix undefined behavior in json.c (Bug#42113)
cce00bef03 Fix ACTION argument of 'display-buffer' call in gud.el
0121db2702 * src/keyboard.c (Fclear_this_command_keys): Doc fix.
b9abf5ceb2 Improve do string of 'man'
b87fc938a0 ; * src/xdisp.c (pos_visible_p): Yet another minor fix for...

3 files changed, 10 insertions, 5 deletions

diff --git a/src/json.c b/src/json.c
index 30027675580..814afc6d741 100644
--- a/src/json.c
+++ b/src/json.c
@@ -365,6 +365,7 @@ lisp_to_json_toplevel_1 (Lisp_Object lisp,
           Lisp_Object key = HASH_KEY (h, i);
           if (!EQ (key, Qunbound))
             {
+              CHECK_STRING (key);
               Lisp_Object ekey = json_encode (key);
               /* We can't specify the length, so the string must be
                NUL-terminated.  */
@@ -975,6 +976,7 @@ usage: (json-parse-string STRING &rest ARGS) */)
 #endif
 
   Lisp_Object string = args[0];
+  CHECK_STRING (string);
   Lisp_Object encoded = json_encode (string);
   check_string_without_embedded_nuls (encoded);
   struct json_configuration conf =
diff --git a/src/keyboard.c b/src/keyboard.c
index f9b9399d502..5fa58abce1d 100644
--- a/src/keyboard.c
+++ b/src/keyboard.c
@@ -10531,7 +10531,7 @@ The value is always a vector.  */)
 DEFUN ("clear-this-command-keys", Fclear_this_command_keys,
        Sclear_this_command_keys, 0, 1, 0,
        doc: /* Clear out the vector that `this-command-keys' returns.
-Also clear the record of the last 100 events, unless optional arg
+Also clear the record of the last 300 input events, unless optional arg
 KEEP-RECORD is non-nil.  */)
   (Lisp_Object keep_record)
 {
diff --git a/src/xdisp.c b/src/xdisp.c
index e454fd7b83f..92afcccd388 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -1872,10 +1872,13 @@ pos_visible_p (struct window *w, ptrdiff_t charpos, int *x, int *y,
                   /* Account for line-number display, if IT3 still
                      didn't.  This can happen if START - 1 is the
                      first or the last character on its display line.  */
-                  if (it3.lnum_pixel_width > 0)
-                    top_x += it3.lnum_pixel_width;
-                  else if (it.line_number_produced_p)
-                    top_x += it.lnum_pixel_width;
+                  if (!it3.line_number_produced_p)
+                    {
+                      if (it3.lnum_pixel_width > 0)
+                        top_x += it3.lnum_pixel_width;
+                      else if (it.line_number_produced_p)
+                        top_x += it.lnum_pixel_width;
+                    }
                   /* Normally, we would exit the above loop because we
                      found the display element whose character
                      position is CHARPOS.  For the contingency that we