Merge from origin/emacs-26

a87ce5c4b4 * src/lisp.h (GCALIGNED): Clarify comment (Bug#29040).
8a31e9993f ; etc/NEWS: Add cpp-message-min-time-interval.  (Bug#28961)
ac0bb9a192 Improve the doc of eshell-cmpl-* custom variables (Bug#25069)
36400c7dc9 Fix mouse-scrollbar offset on GNUstep and old macOS (bug#2...
04bc1410c2 Merge from Gnulib
6b08ad5263 Fix alignment portability problems
a9f8706fa8 Fix completion of colon after CSS property (Bug#29056)
9031dec527 ; * src/alloc.c (sweep_symbols): Fix last change.
fdd3dcfa4e * src/alloc.c (sweep_symbols): Tweak last change
27964af438 In frame parameters documentation mention desktop saving/r...
1bd4e7c243 ; Fix typo in ChangeLog.3
4182a60d31 Don't have frameset save the 'client' parameter (Bug#29067)
9d31a97092 ; Spelling fixes
460a25f212 Handle generic variables in cl-defgeneric Edebug spec
dc0a25c2f9 Give a more sensible message if file-attributes fails (Bug...
8453423c7c Avoid wrong value from file-attributes on Linux kernel bef...
70621e2571 Fix customization of debugger-print-function (Bug#29077)

# Conflicts:
#	etc/NEWS

7 files changed, 57 insertions, 31 deletions

diff --git a/src/ChangeLog.13 b/src/ChangeLog.13
index e252acfbdb1..9f3fdee210a 100644
--- a/src/ChangeLog.13
+++ b/src/ChangeLog.13
@@ -16581,7 +16581,7 @@
         (characterIndexForPoint:): Adjust return type depending on GNUstep
         version.
         (mouseDown:): delta is CGFloat.
-        (updateFrameSize): Remove unised variable f.
+        (updateFrameSize): Remove unused variable f.
         (initFrameFromEmacs): Move toggleButton inside NS_IMPL_COCOA.
         Cast float to EmacsCGFloat.
         (windowWillUseStandardFrame:defaultFrame:): Set maximized_height
@@ -16593,7 +16593,7 @@
         (setPosition:portion:whole:): por is CGFloat.
         (getMouseMotionPart:window:x:y:): Add F suffix to float.
         (mouseDown:): Use CGFloat.
-        (mouseDragged:): Remove unised variable edge.
+        (mouseDragged:): Remove unused variable edge.
         (EmacsDocument): Implement for NS_IMPL_GNUSTEP.
 
         * nsterm.h (EmacsCGFloat): Typedef for OSX and GNUstep when the size
diff --git a/src/alloc.c b/src/alloc.c
index 11afdfd7cc0..0fc79fe68ac 100644
--- a/src/alloc.c
+++ b/src/alloc.c
@@ -621,6 +621,12 @@ buffer_memory_full (ptrdiff_t nbytes)
 #endif
 }
 
+/* A common multiple of the positive integers A and B.  Ideally this
+   would be the least common multiple, but there's no way to do that
+   as a constant expression in C, so do the best that we can easily do.  */
+#define COMMON_MULTIPLE(a, b) \
+  ((a) % (b) == 0 ? (a) : (b) % (a) == 0 ? (b) : (a) * (b))
+
 #ifndef XMALLOC_OVERRUN_CHECK
 #define XMALLOC_OVERRUN_CHECK_OVERHEAD 0
 #else
@@ -7024,10 +7030,16 @@ sweep_symbols (void)
         {
           if (!sym->s.gcmarkbit)
             {
-              if (sym->s.redirect == SYMBOL_LOCALIZED
-                  /* Already freed?  */
-                  && !EQ (sym->s.function, Vdead))
-                xfree (SYMBOL_BLV (&sym->s));
+              if (sym->s.redirect == SYMBOL_LOCALIZED)
+                {
+                  xfree (SYMBOL_BLV (&sym->s));
+                  /* At every GC we sweep all symbol_blocks and rebuild the
+                     symbol_free_list, so those symbols which stayed unused
+                     between the two will be re-swept.
+                     So we have to make sure we don't re-free this blv next
+                     time we sweep this symbol_block (bug#29066).  */
+                  sym->s.redirect = SYMBOL_PLAINVAL;
+                }
               sym->s.next = symbol_free_list;
               symbol_free_list = &sym->s;
               symbol_free_list->function = Vdead;
diff --git a/src/buffer.c b/src/buffer.c
index 9635733fcff..15735a298ad 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -61,7 +61,7 @@ struct buffer *all_buffers;
    Setting the default value also goes through the alist of buffers
    and stores into each buffer that does not say it has a local value.  */
 
-struct buffer alignas (GCALIGNMENT) buffer_defaults;
+struct buffer GCALIGNED buffer_defaults;
 
 /* This structure marks which slots in a buffer have corresponding
    default values in buffer_defaults.
@@ -84,7 +84,7 @@ struct buffer buffer_local_flags;
 /* This structure holds the names of symbols whose values may be
    buffer-local.  It is indexed and accessed in the same way as the above.  */
 
-struct buffer alignas (GCALIGNMENT) buffer_local_symbols;
+struct buffer GCALIGNED buffer_local_symbols;
 
 /* Return the symbol of the per-buffer variable at offset OFFSET in
    the buffer structure.  */
diff --git a/src/dired.c b/src/dired.c
index 28d1cffb44c..239b1acd1fb 100644
--- a/src/dired.c
+++ b/src/dired.c
@@ -953,7 +953,14 @@ file_attributes (int fd, char const *name,
     {
       record_unwind_protect_int (close_file_unwind, namefd);
       if (fstat (namefd, &s) != 0)
-        err = errno;
+        {
+          err = errno;
+          /* The Linux kernel before version 3.6 does not support
+             fstat on O_PATH file descriptors.  Handle this error like
+             missing support for O_PATH.  */
+          if (err == EBADF)
+            err = EINVAL;
+        }
       else
         {
           err = 0;
diff --git a/src/lisp.h b/src/lisp.h
index 43b3ec618f0..a71ba22618e 100644
--- a/src/lisp.h
+++ b/src/lisp.h
@@ -228,14 +228,12 @@ extern bool suppress_checking EXTERNALLY_VISIBLE;
 
    USE_LSB_TAG not only requires the least 3 bits of pointers returned by
    malloc to be 0 but also needs to be able to impose a mult-of-8 alignment
-   on the few static Lisp_Objects used: lispsym, all the defsubr, and
-   the two special buffers buffer_defaults and buffer_local_symbols.  */
+   on the few static Lisp_Objects used, all of which are aligned via
+   the GCALIGN macro defined below.  */
 
 enum Lisp_Bits
   {
-    /* 2**GCTYPEBITS.  This must be a macro that expands to a literal
-       integer constant, for MSVC.  */
-#define GCALIGNMENT 8
+    GCALIGNMENT = 1 << GCTYPEBITS,
 
     /* Number of bits in a Lisp_Object value, not counting the tag.  */
     VALBITS = EMACS_INT_WIDTH - GCTYPEBITS,
@@ -247,10 +245,6 @@ enum Lisp_Bits
     FIXNUM_BITS = VALBITS + 1
   };
 
-#if GCALIGNMENT != 1 << GCTYPEBITS
-# error "GCALIGNMENT and GCTYPEBITS are inconsistent"
-#endif
-
 /* The maximum value that can be stored in a EMACS_INT, assuming all
    bits other than the type bits contribute to a nonnegative signed value.
    This can be used in #if, e.g., '#if USE_LSB_TAG' below expands to an
@@ -277,18 +271,16 @@ DEFINE_GDB_SYMBOL_END (VALMASK)
 error !;
 #endif
 
+/* Declare an object to have an address that is a multiple of
+   GCALIGNMENT.  This is a no-op if the object's natural alignment is
+   already a multiple of GCALIGNMENT.  alignas is not suitable here,
+   as it fails if the object's natural alignment exceeds GCALIGNMENT.  */
 #ifdef HAVE_STRUCT_ATTRIBUTE_ALIGNED
 # define GCALIGNED __attribute__ ((aligned (GCALIGNMENT)))
 #else
 # define GCALIGNED /* empty */
 #endif
 
-/* A common multiple of the positive integers A and B.  Ideally this
-   would be the least common multiple, but there's no way to do that
-   as a constant expression in C, so do the best that we can easily do.  */
-#define COMMON_MULTIPLE(a, b) \
-  ((a) % (b) == 0 ? (a) : (b) % (a) == 0 ? (b) : (a) * (b))
-
 /* Some operations are so commonly executed that they are implemented
    as macros, not functions, because otherwise runtime performance would
    suffer too much when compiling with GCC without optimization.
@@ -2946,7 +2938,7 @@ CHECK_NUMBER_CDR (Lisp_Object x)
 #ifdef _MSC_VER
 #define DEFUN(lname, fnname, sname, minargs, maxargs, intspec, doc)     \
    Lisp_Object fnname DEFUN_ARGS_ ## maxargs ;                          \
-   static struct Lisp_Subr alignas (GCALIGNMENT) sname =                \
+   static struct Lisp_Subr GCALIGNED sname =                            \
    { { (PVEC_SUBR << PSEUDOVECTOR_AREA_BITS)                            \
        | (sizeof (struct Lisp_Subr) / sizeof (EMACS_INT)) },            \
       { (Lisp_Object (__cdecl *)(void))fnname },                        \
@@ -2954,7 +2946,7 @@ CHECK_NUMBER_CDR (Lisp_Object x)
    Lisp_Object fnname
 #else  /* not _MSC_VER */
 #define DEFUN(lname, fnname, sname, minargs, maxargs, intspec, doc)     \
-   static struct Lisp_Subr alignas (GCALIGNMENT) sname =                \
+   static struct Lisp_Subr GCALIGNED sname =                            \
      { { PVEC_SUBR << PSEUDOVECTOR_AREA_BITS },                         \
        { .a ## maxargs = fnname },                                      \
        minargs, maxargs, lname, intspec, 0};                            \
diff --git a/src/nsterm.m b/src/nsterm.m
index a382e5f7130..5c29f039e51 100644
--- a/src/nsterm.m
+++ b/src/nsterm.m
@@ -8912,10 +8912,20 @@ not_in_argv (NSString *arg)
         }
       last_mouse_offset = kloc;
 
-      if (part != NSScrollerKnob)
-        /* this is a slot click on GNUstep: go straight there */
+      /* if knob, tell emacs a location offset by knob pos
+         (to indicate top of handle) */
+      if (part == NSScrollerKnob)
+        pos = (loc - last_mouse_offset);
+      else
+        /* else this is a slot click on GNUstep: go straight there */
         pos = loc;
 
+      /* If there are buttons in the scroller area, we need to
+         recalculate pos as emacs expects the scroller slot to take up
+         the entire available length.  */
+      if (length != pixel_length)
+        pos = pos * pixel_length / length;
+
       /* send a fake mouse-up to super to preempt modal -trackKnob: mode */
       fake_event = [NSEvent mouseEventWithType: NSEventTypeLeftMouseUp
                                       location: [e locationInWindow]
@@ -8980,6 +8990,13 @@ not_in_argv (NSString *arg)
         }
 
       pos = (loc - last_mouse_offset);
+
+      /* If there are buttons in the scroller area, we need to
+         recalculate pos as emacs expects the scroller slot to take up
+         the entire available length.  */
+      if (length != pixel_length)
+        pos = pos * pixel_length / length;
+
       [self sendScrollEventAtLoc: pos fromEvent: e];
 }
 
diff --git a/src/thread.c b/src/thread.c
index 7a670ba410b..03f5b31855e 100644
--- a/src/thread.c
+++ b/src/thread.c
@@ -26,9 +26,7 @@ along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */
 #include "coding.h"
 #include "syssignal.h"
 
-#define THREAD_ALIGNMENT COMMON_MULTIPLE (alignof (max_align_t), GCALIGNMENT)
-
-static struct thread_state alignas (THREAD_ALIGNMENT) main_thread;
+static struct thread_state GCALIGNED main_thread;
 
 struct thread_state *current_thread = &main_thread;