1 files changed, 90 insertions, 0 deletions
diff --git a/lib/filenamecat-lgpl.c b/lib/filenamecat-lgpl.c
new file mode 100644
index 0000000..7e77d35
--- /dev/null
+++ b/lib/filenamecat-lgpl.c
@@ -0,0 +1,90 @@
+/* Concatenate two arbitrary file names.
+
+   Copyright (C) 1996-2007, 2009-2020 Free Software Foundation, Inc.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
+
+/* Written by Jim Meyering.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include "filenamecat.h"
+
+#include <stdlib.h>
+#include <string.h>
+
+#include "basename-lgpl.h"
+#include "filename.h"
+
+#if ! HAVE_MEMPCPY && ! defined mempcpy
+# define mempcpy(D, S, N) ((void *) ((char *) memcpy (D, S, N) + (N)))
+#endif
+
+/* Concatenate two file name components, DIR and BASE, in
+   newly-allocated storage and return the result.
+   The resulting file name F is such that the commands "ls F" and "(cd
+   DIR; ls ./BASE)" refer to the same file.  If necessary, put
+   a separator between DIR and BASE in the result.  Typically this
+   separator is "/", but in rare cases it might be ".".
+   In any case, if BASE_IN_RESULT is non-NULL, set
+   *BASE_IN_RESULT to point to the copy of BASE at the end of the
+   returned concatenation.
+
+   If malloc fails, return NULL with errno set.  */
+
+char *
+mfile_name_concat (char const *dir, char const *base, char **base_in_result)
+{
+  char const *dirbase = last_component (dir);
+  size_t dirbaselen = base_len (dirbase);
+  size_t dirlen = dirbase - dir + dirbaselen;
+  size_t baselen = strlen (base);
+  char sep = '\0';
+  if (dirbaselen)
+    {
+      /* DIR is not a file system root, so separate with / if needed.  */
+      if (! ISSLASH (dir[dirlen - 1]) && ! ISSLASH (*base))
+        sep = '/';
+    }
+  else if (ISSLASH (*base))
+    {
+      /* DIR is a file system root and BASE begins with a slash, so
+         separate with ".".  For example, if DIR is "/" and BASE is
+         "/foo" then return "/./foo", as "//foo" would be wrong on
+         some POSIX systems.  A fancier algorithm could omit "." in
+         some cases but is not worth the trouble.  */
+      sep = '.';
+    }
+
+  char *p_concat = malloc (dirlen + (sep != '\0')  + baselen + 1);
+  if (p_concat == NULL)
+    return NULL;
+
+  {
+    char *p;
+
+    p = mempcpy (p_concat, dir, dirlen);
+    *p = sep;
+    p += sep != '\0';
+
+    if (base_in_result)
+      *base_in_result = p;
+
+    p = mempcpy (p, base, baselen);
+    *p = '\0';
+  }
+
+  return p_concat;
+}