Let Gnulib deal with malloc/realloc 0

Instead of worrying about whether malloc and realloc yield a
non-null pointer when given size 0 (the traditional behavior
recommended by Doug McIlroy, and the only behavior that makes
sense for Emacs), let Gnulib arrange for the traditional behavior.
* admin/merge-gnulib (GNULIB_MODULES): Add malloc-gnu (which we
were already depending on indirectly) and realloc-posix.
* lib/gnulib.mk.in, m4/gnulib-comp.m4:
Regenerate by running admin/merge-gnulib.

admin/merge-gnulib

@@ -41,11 +41,11 @@ GNULIB_MODULES='
   free-posix fstatat fsusage fsync futimens
   getline getloadavg getopt-gnu getrandom gettime gettimeofday gitlog-to-changelog
   ieee754-h ignore-value intprops largefile libgmp lstat
-  manywarnings memmem-simple mempcpy memrchr memset_explicit
+  malloc-gnu manywarnings memmem-simple mempcpy memrchr memset_explicit
   minmax mkostemp mktime
   nanosleep nproc nstrftime
   pathmax pipe2 pselect pthread_sigmask
-  qcopy-acl readlink readlinkat regex
+  qcopy-acl readlink readlinkat realloc-posix regex
   sig2str sigdescr_np socklen stat-time std-gnu11
   stdc_bit_width stdc_count_ones stdc_trailing_zeros
   stdckdint-h stddef-h stdio-h

lib/gnulib.mk.in

@@ -132,6 +132,7 @@
 #  largefile \
 #  libgmp \
 #  lstat \
+#  malloc-gnu \
 #  manywarnings \
 #  memmem-simple \
 #  mempcpy \
@@ -150,6 +151,7 @@
 #  qcopy-acl \
 #  readlink \
 #  readlinkat \
+#  realloc-posix \
 #  regex \
 #  sig2str \
 #  sigdescr_np \
@@ -1478,14 +1480,12 @@ gl_GNULIB_ENABLED_03e0aaad4cb89ca757653bd367a6ccb7_CONDITION = @gl_GNULIB_ENABLE
 gl_GNULIB_ENABLED_260941c0e5dc67ec9e87d1fb321c300b_CONDITION = @gl_GNULIB_ENABLED_260941c0e5dc67ec9e87d1fb321c300b_CONDITION@
 gl_GNULIB_ENABLED_5264294aa0a5557541b53c8c741f7f31_CONDITION = @gl_GNULIB_ENABLED_5264294aa0a5557541b53c8c741f7f31_CONDITION@
 gl_GNULIB_ENABLED_6099e9737f757db36c47fa9d9f02e88c_CONDITION = @gl_GNULIB_ENABLED_6099e9737f757db36c47fa9d9f02e88c_CONDITION@
-gl_GNULIB_ENABLED_61bcaca76b3e6f9ae55d57a1c3193bc4_CONDITION = @gl_GNULIB_ENABLED_61bcaca76b3e6f9ae55d57a1c3193bc4_CONDITION@
 gl_GNULIB_ENABLED_8444034ea779b88768865bb60b4fb8c9_CONDITION = @gl_GNULIB_ENABLED_8444034ea779b88768865bb60b4fb8c9_CONDITION@
 gl_GNULIB_ENABLED_925677f0343de64b89a9f0c790b4104c_CONDITION = @gl_GNULIB_ENABLED_925677f0343de64b89a9f0c790b4104c_CONDITION@
 gl_GNULIB_ENABLED_a9786850e999ae65a836a6041e8e5ed1_CONDITION = @gl_GNULIB_ENABLED_a9786850e999ae65a836a6041e8e5ed1_CONDITION@
 gl_GNULIB_ENABLED_be453cec5eecf5731a274f2de7f2db36_CONDITION = @gl_GNULIB_ENABLED_be453cec5eecf5731a274f2de7f2db36_CONDITION@
 gl_GNULIB_ENABLED_cloexec_CONDITION = @gl_GNULIB_ENABLED_cloexec_CONDITION@
 gl_GNULIB_ENABLED_dirfd_CONDITION = @gl_GNULIB_ENABLED_dirfd_CONDITION@
-gl_GNULIB_ENABLED_e80bf6f757095d2e5fc94dafb8f8fc8b_CONDITION = @gl_GNULIB_ENABLED_e80bf6f757095d2e5fc94dafb8f8fc8b_CONDITION@
 gl_GNULIB_ENABLED_endian_CONDITION = @gl_GNULIB_ENABLED_endian_CONDITION@
 gl_GNULIB_ENABLED_euidaccess_CONDITION = @gl_GNULIB_ENABLED_euidaccess_CONDITION@
 gl_GNULIB_ENABLED_fd38c7e463b54744b77b98aeafb4fa7c_CONDITION = @gl_GNULIB_ENABLED_fd38c7e463b54744b77b98aeafb4fa7c_CONDITION@
@@ -2688,9 +2688,7 @@ endif
 ## begin gnulib module malloc-gnu
 ifeq (,$(OMIT_GNULIB_MODULE_malloc-gnu))
 
-ifneq (,$(gl_GNULIB_ENABLED_e80bf6f757095d2e5fc94dafb8f8fc8b_CONDITION))
 
-endif
 EXTRA_DIST += malloc.c
 
 EXTRA_libgnu_a_SOURCES += malloc.c
@@ -2933,12 +2931,10 @@ endif
 ## begin gnulib module realloc-posix
 ifeq (,$(OMIT_GNULIB_MODULE_realloc-posix))
 
-ifneq (,$(gl_GNULIB_ENABLED_61bcaca76b3e6f9ae55d57a1c3193bc4_CONDITION))
 ifneq (,$(GL_COND_OBJ_REALLOC_POSIX_CONDITION))
 libgnu_a_SOURCES += realloc.c
 endif
 
-endif
 endif
 ## end   gnulib module realloc-posix
 

m4/gnulib-comp.m4

@@ -424,6 +424,11 @@ AC_DEFUN([gl_INIT],
   ])
   gl_SYS_STAT_MODULE_INDICATOR([lstat])
   gl_MODULE_INDICATOR([lstat])
+  gl_FUNC_MALLOC_GNU
+  if test $REPLACE_MALLOC_FOR_MALLOC_GNU = 1; then
+    AC_LIBOBJ([malloc])
+  fi
+  gl_STDLIB_MODULE_INDICATOR([malloc-gnu])
   AC_REQUIRE([gl_FUNC_MALLOC_POSIX])
   if test $REPLACE_MALLOC_FOR_MALLOC_POSIX = 1; then
     AC_LIBOBJ([malloc])
@@ -502,6 +507,11 @@ AC_DEFUN([gl_INIT],
   gl_CONDITIONAL([GL_COND_OBJ_READLINKAT],
                  [test $HAVE_READLINKAT = 0 || test $REPLACE_READLINKAT = 1])
   gl_UNISTD_MODULE_INDICATOR([readlinkat])
+  gl_FUNC_REALLOC_POSIX
+  gl_FUNC_REALLOC_0_NONNULL
+  gl_CONDITIONAL([GL_COND_OBJ_REALLOC_POSIX],
+                 [test $REPLACE_REALLOC_FOR_REALLOC_POSIX != 0])
+  gl_STDLIB_MODULE_INDICATOR([realloc-posix])
   gl_REGEX
   gl_CONDITIONAL([GL_COND_OBJ_REGEX], [test $ac_use_included_regex = yes])
   AM_COND_IF([GL_COND_OBJ_REGEX], [
@@ -684,12 +694,10 @@ AC_DEFUN([gl_INIT],
   gl_gnulib_enabled_8444034ea779b88768865bb60b4fb8c9=false
   gl_gnulib_enabled_a9786850e999ae65a836a6041e8e5ed1=false
   gl_gnulib_enabled_lchmod=false
-  gl_gnulib_enabled_e80bf6f757095d2e5fc94dafb8f8fc8b=false
   gl_gnulib_enabled_5264294aa0a5557541b53c8c741f7f31=false
   gl_gnulib_enabled_open=false
   gl_gnulib_enabled_03e0aaad4cb89ca757653bd367a6ccb7=false
   gl_gnulib_enabled_rawmemchr=false
-  gl_gnulib_enabled_61bcaca76b3e6f9ae55d57a1c3193bc4=false
   gl_gnulib_enabled_6099e9737f757db36c47fa9d9f02e88c=false
   gl_gnulib_enabled_strtoll=false
   gl_gnulib_enabled_utimens=false
@@ -811,7 +819,6 @@ AC_DEFUN([gl_INIT],
     if $gl_gnulib_enabled_8444034ea779b88768865bb60b4fb8c9; then :; else
       AC_PROG_MKDIR_P
       gl_gnulib_enabled_8444034ea779b88768865bb60b4fb8c9=true
-      func_gl_gnulib_m4code_61bcaca76b3e6f9ae55d57a1c3193bc4
     fi
   }
   func_gl_gnulib_m4code_a9786850e999ae65a836a6041e8e5ed1 ()
@@ -827,9 +834,6 @@ AC_DEFUN([gl_INIT],
       if test $HAVE_GROUP_MEMBER = 0; then
         func_gl_gnulib_m4code_getgroups
       fi
-      if test $HAVE_GROUP_MEMBER = 0; then
-        func_gl_gnulib_m4code_e80bf6f757095d2e5fc94dafb8f8fc8b
-      fi
     fi
   }
   func_gl_gnulib_m4code_lchmod ()
@@ -844,17 +848,6 @@ AC_DEFUN([gl_INIT],
       gl_gnulib_enabled_lchmod=true
     fi
   }
-  func_gl_gnulib_m4code_e80bf6f757095d2e5fc94dafb8f8fc8b ()
-  {
-    if $gl_gnulib_enabled_e80bf6f757095d2e5fc94dafb8f8fc8b; then :; else
-      gl_FUNC_MALLOC_GNU
-      if test $REPLACE_MALLOC_FOR_MALLOC_GNU = 1; then
-        AC_LIBOBJ([malloc])
-      fi
-      gl_STDLIB_MODULE_INDICATOR([malloc-gnu])
-      gl_gnulib_enabled_e80bf6f757095d2e5fc94dafb8f8fc8b=true
-    fi
-  }
   func_gl_gnulib_m4code_5264294aa0a5557541b53c8c741f7f31 ()
   {
     if $gl_gnulib_enabled_5264294aa0a5557541b53c8c741f7f31; then :; else
@@ -899,17 +892,6 @@ AC_DEFUN([gl_INIT],
       gl_gnulib_enabled_rawmemchr=true
     fi
   }
-  func_gl_gnulib_m4code_61bcaca76b3e6f9ae55d57a1c3193bc4 ()
-  {
-    if $gl_gnulib_enabled_61bcaca76b3e6f9ae55d57a1c3193bc4; then :; else
-      gl_FUNC_REALLOC_POSIX
-      gl_FUNC_REALLOC_0_NONNULL
-      gl_CONDITIONAL([GL_COND_OBJ_REALLOC_POSIX],
-                     [test $REPLACE_REALLOC_FOR_REALLOC_POSIX != 0])
-      gl_STDLIB_MODULE_INDICATOR([realloc-posix])
-      gl_gnulib_enabled_61bcaca76b3e6f9ae55d57a1c3193bc4=true
-    fi
-  }
   func_gl_gnulib_m4code_6099e9737f757db36c47fa9d9f02e88c ()
   {
     if $gl_gnulib_enabled_6099e9737f757db36c47fa9d9f02e88c; then :; else
@@ -1011,9 +993,6 @@ AC_DEFUN([gl_INIT],
   if test $ac_use_included_regex = yes; then
     func_gl_gnulib_m4code_fd38c7e463b54744b77b98aeafb4fa7c
   fi
-  if test $ac_use_included_regex = yes; then
-    func_gl_gnulib_m4code_e80bf6f757095d2e5fc94dafb8f8fc8b
-  fi
   if test $ac_use_included_regex = yes; then
     func_gl_gnulib_m4code_verify
   fi
@@ -1047,12 +1026,10 @@ AC_DEFUN([gl_INIT],
   AM_CONDITIONAL([gl_GNULIB_ENABLED_8444034ea779b88768865bb60b4fb8c9], [$gl_gnulib_enabled_8444034ea779b88768865bb60b4fb8c9])
   AM_CONDITIONAL([gl_GNULIB_ENABLED_a9786850e999ae65a836a6041e8e5ed1], [$gl_gnulib_enabled_a9786850e999ae65a836a6041e8e5ed1])
   AM_CONDITIONAL([gl_GNULIB_ENABLED_lchmod], [$gl_gnulib_enabled_lchmod])
-  AM_CONDITIONAL([gl_GNULIB_ENABLED_e80bf6f757095d2e5fc94dafb8f8fc8b], [$gl_gnulib_enabled_e80bf6f757095d2e5fc94dafb8f8fc8b])
   AM_CONDITIONAL([gl_GNULIB_ENABLED_5264294aa0a5557541b53c8c741f7f31], [$gl_gnulib_enabled_5264294aa0a5557541b53c8c741f7f31])
   AM_CONDITIONAL([gl_GNULIB_ENABLED_open], [$gl_gnulib_enabled_open])
   AM_CONDITIONAL([gl_GNULIB_ENABLED_03e0aaad4cb89ca757653bd367a6ccb7], [$gl_gnulib_enabled_03e0aaad4cb89ca757653bd367a6ccb7])
   AM_CONDITIONAL([gl_GNULIB_ENABLED_rawmemchr], [$gl_gnulib_enabled_rawmemchr])
-  AM_CONDITIONAL([gl_GNULIB_ENABLED_61bcaca76b3e6f9ae55d57a1c3193bc4], [$gl_gnulib_enabled_61bcaca76b3e6f9ae55d57a1c3193bc4])
   AM_CONDITIONAL([gl_GNULIB_ENABLED_6099e9737f757db36c47fa9d9f02e88c], [$gl_gnulib_enabled_6099e9737f757db36c47fa9d9f02e88c])
   AM_CONDITIONAL([gl_GNULIB_ENABLED_strtoll], [$gl_gnulib_enabled_strtoll])
   AM_CONDITIONAL([gl_GNULIB_ENABLED_utimens], [$gl_gnulib_enabled_utimens])