Adjust to recent Gnulib changes

The latest Gnulib merge brought in free-posix, which causes 'free'
to preserve errno.  This lets us simplify some Emacs code that
calls 'free'.
* admin/merge-gnulib (GNULIB_MODULES): Add free-posix.
This module is pulled in by canonicalize-lgpl anyway,
so we might as well rely on it.
* lib-src/emacsclient.c (get_current_dir_name):
Sync better with src/sysdep.c.
* lib-src/etags.c (process_file_name, etags_mktmp):
* lib-src/update-game-score.c (unlock_file):
* src/fileio.c (file_accessible_directory_p):
* src/sysdep.c (get_current_dir_name_or_unreachable):
Simplify by assuming that 'free' preserves errno.
* src/alloc.c (malloc_unblock_input):
Preserve errno, so that xfree preserves errno.
* src/sysdep.c (get_current_dir_name_or_unreachable):
Simplify by using strdup instead of malloc+memcpy.
No need for realloc (and the old code leaked memory anyway on
failure); just use free+malloc.

3 files changed, 12 insertions, 23 deletions

diff --git a/src/alloc.c b/src/alloc.c
index adbfa1883c5..0b387dd8c1b 100644
--- a/src/alloc.c
+++ b/src/alloc.c
@@ -732,7 +732,11 @@ static void
 malloc_unblock_input (void)
 {
   if (block_input_in_memory_allocators)
-    unblock_input ();
+    {
+      int err = errno;
+      unblock_input ();
+      errno = err;
+    }
 }
 # define MALLOC_BLOCK_INPUT malloc_block_input ()
 # define MALLOC_UNBLOCK_INPUT malloc_unblock_input ()
diff --git a/src/fileio.c b/src/fileio.c
index 651e765fca4..23b4523c944 100644
--- a/src/fileio.c
+++ b/src/fileio.c
@@ -3050,7 +3050,6 @@ file_accessible_directory_p (Lisp_Object file)
   ptrdiff_t len = SBYTES (file);
   char const *dir;
   bool ok;
-  int saved_errno;
   USE_SAFE_ALLOCA;
 
   /* Normally a file "FOO" is an accessible directory if "FOO/." exists.
@@ -3075,9 +3074,7 @@ file_accessible_directory_p (Lisp_Object file)
     }
 
   ok = file_access_p (dir, F_OK);
-  saved_errno = errno;
   SAFE_FREE ();
-  errno = saved_errno;
   return ok;
 #endif  /* !DOS_NT */
 }
diff --git a/src/sysdep.c b/src/sysdep.c
index 29c88f5308e..eeb9d184940 100644
--- a/src/sysdep.c
+++ b/src/sysdep.c
@@ -314,33 +314,21 @@ get_current_dir_name_or_unreachable (void)
       && emacs_fstatat (AT_FDCWD, ".", &dotstat, 0) == 0
       && dotstat.st_ino == pwdstat.st_ino
       && dotstat.st_dev == pwdstat.st_dev)
-    {
-      char *buf = malloc (pwdlen + 1);
-      if (!buf)
-        return NULL;
-      return memcpy (buf, pwd, pwdlen + 1);
-    }
+    return strdup (pwd);
   else
     {
       ptrdiff_t buf_size = min (bufsize_max, 1024);
-      char *buf = malloc (buf_size);
-      if (!buf)
-        return NULL;
       for (;;)
         {
+          char *buf = malloc (buf_size);
+          if (!buf)
+            return NULL;
           if (getcwd (buf, buf_size) == buf)
             return buf;
-          int getcwd_errno = errno;
-          if (getcwd_errno != ERANGE || buf_size == bufsize_max)
-            {
-              free (buf);
-              errno = getcwd_errno;
-              return NULL;
-            }
+          free (buf);
+          if (errno != ERANGE || buf_size == bufsize_max)
+            return NULL;
           buf_size = buf_size <= bufsize_max / 2 ? 2 * buf_size : bufsize_max;
-          buf = realloc (buf, buf_size);
-          if (!buf)
-            return NULL;
         }
     }
 }