Merge from origin/emacs-26

86d2169 Avoid ridiculously high stack limit requests on macOS
ac3622c Improve documentation of 'read-hide-char'

# Conflicts:
#	src/emacs.c

2 files changed, 9 insertions, 3 deletions

diff --git a/src/emacs.c b/src/emacs.c
index b7a82793523..07df191035c 100644
--- a/src/emacs.c
+++ b/src/emacs.c
@@ -881,7 +881,8 @@ main (int argc, char **argv)
             newlim = rlim.rlim_max;
           newlim -= newlim % pagesize;
 
-          if (pagesize <= newlim - lim)
+          if (newlim > lim      /* in case rlim_t is an unsigned type */
+              && pagesize <= newlim - lim)
             {
               rlim.rlim_cur = newlim;
               if (setrlimit (RLIMIT_STACK, &rlim) == 0)
@@ -890,6 +891,8 @@ main (int argc, char **argv)
         }
       /* If the stack is big enough, let regex-emacs.c use more of it
          before falling back to heap allocation.  */
+      if (lim < extra)
+        lim = extra;    /* avoid wrap-around in unsigned subtraction */
       ptrdiff_t max_failures
         = min (lim - extra, min (PTRDIFF_MAX, SIZE_MAX)) / ratio;
       emacs_re_safe_alloca = max (max_failures * min_ratio, MAX_ALLOCA);
diff --git a/src/minibuf.c b/src/minibuf.c
index 751d6bda168..9395dc8df2f 100644
--- a/src/minibuf.c
+++ b/src/minibuf.c
@@ -2058,8 +2058,11 @@ properties.  */);
 
   DEFVAR_LISP ("read-hide-char", Vread_hide_char,
                doc: /* Whether to hide input characters in noninteractive mode.
-It must be a character, which will be used to mask the input
-characters.  This variable should never be set globally.  */);
+If non-nil, it must be a character, which will be used to mask the
+input characters.  This variable should never be set globally.
+
+This variable also overrides the default character that `read-passwd'
+uses to hide passwords.  */);
   Vread_hide_char = Qnil;
 
   defsubr (&Sactive_minibuffer_window);