core: Add gpgrt_fnameconcat and gpgrt_absfnameconcat.

* src/gpg-error.h.in (gpgrt_fnameconcat): New.
(gpgrt_absfnameconcat): New.
* src/visibility.c (gpgrt_fnameconcat, gpgrt_absfnameconcat): New.
* src/stringutils.c: New file.
(_gpgrt_vfnameconcat): New.
(_gpgrt_fnameconcat, _gpgrt_absfnameconcat): New.
* src/gpg-error.def.in: Add new functions.
* src/gpg-error.vers: Ditto.
* src/sysutils.c: Include pwd.h.
(_gpgrt_getpwdir): New.
* configure.ac: Test for pwd.h, getpwnam, getpwuid, and their _r
variants.
* src/Makefile.am (libgpg_error_la_SOURCES): Add new file.

* tests/t-stringutils.c: New.
* tests/t-common.h (xmalloc, xstrdup, xfree): New.
(die): Kludge to avoid compiler warnings.
--

The new functions are based on the code of make_filename from GnuPG.
They have been written by me ages ago with only minor modifications by
David Shaw.  I re-license them from LGPL-3.0+ OR GPL-2.0+ to
LGPL-2.1-or-later.

Signed-off-by: Werner Koch <wk@gnupg.org>

3 files changed, 312 insertions, 1 deletions

diff --git a/tests/Makefile.am b/tests/Makefile.am
index ea02da1..39ca241 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -28,7 +28,7 @@ endif
 gpg_error_lib = ../src/libgpg-error.la
 
 TESTS = t-version t-strerror t-syserror t-lock t-printf t-poll t-b64 \
-	t-argparse t-logging
+	t-argparse t-logging t-stringutils
 
 AM_CPPFLAGS = -I$(top_builddir)/src $(extra_includes)
 
diff --git a/tests/t-common.h b/tests/t-common.h
index e70e04d..db496e2 100644
--- a/tests/t-common.h
+++ b/tests/t-common.h
@@ -39,6 +39,33 @@ static void fail (const char *format, ...) GPGRT_ATTR_PRINTF(1,2);
 static void show (const char *format, ...) GPGRT_ATTR_PRINTF(1,2);
 
 
+static void *
+xmalloc (size_t n)
+{
+  char *p = gpgrt_malloc (n);
+  if (!p)
+    die ("out of core\n");
+  return p;
+}
+
+static char *
+xstrdup (const char *s)
+{
+  char *p = gpgrt_strdup (s);
+  if (!p)
+    die ("out of core\n");
+  return p;
+}
+
+static void
+xfree (void *p)
+{
+  if (p)
+    gpgrt_free (p);
+}
+
+
+
 static void
 die (const char *format, ...)
 {
@@ -57,6 +84,8 @@ die (const char *format, ...)
 #ifdef HAVE_FLOCKFILE
   funlockfile (stderr);
 #endif
+  xfree (xstrdup (""));  /* To avoid compiler warnings.  */
+  xfree (xmalloc (16));  /* To avoid compiler warnings.  */
   exit (1);
 }
 
diff --git a/tests/t-stringutils.c b/tests/t-stringutils.c
new file mode 100644
index 0000000..01094bf
--- /dev/null
+++ b/tests/t-stringutils.c
@@ -0,0 +1,282 @@
+/* t-stringutils.c - Check some string utilities
+ * Copyright (C) 2020 g10 Code GmbH
+ *
+ * This file is part of Libgpg-error.
+ *
+ * Libgpg-error is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public License
+ * as published by the Free Software Foundation; either version 2.1 of
+ * the License, or (at your option) any later version.
+ *
+ * Libgpg-error 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program; if not, see <https://www.gnu.org/licenses/>.
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+#include <unistd.h>
+#ifdef HAVE_STAT
+# include <sys/stat.h>
+#endif
+#include <sys/types.h>
+#ifdef HAVE_PWD_H
+# include <pwd.h>
+#endif
+#include <errno.h>
+
+#define PGM "t-stringutils"
+#include "t-common.h"
+
+
+static const char *
+my_strusage (int level)
+{
+  const char *p;
+
+  switch (level)
+    {
+    case 9: p = "LGPL-2.1-or-later"; break;
+    case 11: p = PGM; break;
+    default: p = NULL;
+    }
+  return p;
+}
+
+
+const char *
+mygethome (void)
+{
+  static char *home_buffer;
+
+  if (!home_buffer)
+    {
+      char *home = getenv("HOME");
+
+      if(home)
+        home_buffer = xstrdup (home);
+#if defined(HAVE_GETPWUID) && defined(HAVE_PWD_H)
+      else
+        {
+          struct passwd *pwd;
+
+          pwd = getpwuid (getuid());
+          if (pwd)
+            home_buffer = xstrdup (pwd->pw_dir);
+        }
+#endif
+    }
+  return home_buffer;
+}
+
+
+static char *
+mygetcwd (void)
+{
+  char *buffer;
+  size_t size = 100;
+
+  for (;;)
+    {
+      buffer = xmalloc (size+1);
+      if (getcwd (buffer, size) == buffer)
+        return buffer;
+      xfree (buffer);
+      if (errno != ERANGE)
+        die ("error getting current cwd: %s\n", strerror (errno));
+      size *= 2;
+    }
+}
+
+
+static void
+check_fnameconcat (void)
+{
+  char *out;
+  const char *home = mygethome ();
+  size_t homelen = home? strlen (home):0;
+
+  out = gpgrt_fnameconcat ("1", "2", "3", "4", "5", "6", "7", "8", "9", "10",
+                           "1", "2", "3", "4", "5", "6", "7", "8", "9", "10",
+                           "1", "2", "3", "4", "5", "6", "7", "8", "9", "10",
+                           "1", "2", "3", NULL);
+  if (out)
+    fail ("fnameconcat succeeded but should not at line %d\n", __LINE__);
+  else if (errno != EINVAL)
+    fail ("fnameconcat return wrong error at line %d\n", __LINE__);
+  xfree (out);
+
+  out = gpgrt_fnameconcat ("1", "2", "3", "4", "5", "6", "7", "8", "9", "10",
+                           "1", "2", "3", "4", "5", "6", "7", "8", "9", "10",
+                           "1", "2", "3", "4", "5", "6", "7", "8", "9", "10",
+                           "1", "2", "3", "4", NULL);
+  if (out)
+    fail ("fnameconcat succeeded but should not at line %d\n", __LINE__);
+  else if (errno != EINVAL)
+    fail ("fnameconcat return wrong error at line %d\n", __LINE__);
+  xfree (out);
+
+  out = gpgrt_fnameconcat ("1", "2", "3", "4", "5", "6", "7", "8", "9", "10",
+                           "1", "2", "3", "4", "5", "6", "7", "8", "9", "10",
+                           "1", "2", "3", "4", "5", "6", "7", "8", "9", "10",
+                           "1", "2", NULL);
+  if (!out || strcmp (out,
+                      "1/2/3/4/5/6/7/8/9/10/"
+                      "1/2/3/4/5/6/7/8/9/10/"
+                      "1/2/3/4/5/6/7/8/9/10/"
+                      "1/2"))
+    fail ("fnameconcat failed at line %d (out=%s)\n", __LINE__, out);
+  xfree (out);
+
+  out = gpgrt_fnameconcat ("foo", "~/bar", "baz/cde", NULL);
+  if (!out || strcmp (out, "foo/~/bar/baz/cde"))
+    fail ("fnameconcat failed at line %d (out=%s)\n", __LINE__, out);
+  xfree (out);
+
+  out = gpgrt_fnameconcat ("foo", "~/bar", "baz/cde/", NULL);
+  if (!out || strcmp (out, "foo/~/bar/baz/cde/"))
+    fail ("fnameconcat failed at line %d (out=%s)\n", __LINE__, out);
+  xfree (out);
+
+  out = gpgrt_fnameconcat ("/foo", "~/bar", "baz/cde/", NULL);
+  if (!out || strcmp (out, "/foo/~/bar/baz/cde/"))
+    fail ("fnameconcat failed at line %d (out=%s)\n", __LINE__, out);
+  xfree (out);
+
+  out = gpgrt_fnameconcat ("//foo", "~/bar", "baz/cde/", NULL);
+  if (!out || strcmp (out, "//foo/~/bar/baz/cde/"))
+    fail ("fnameconcat failed at line %d (out=%s)\n", __LINE__, out);
+  xfree (out);
+
+  out = gpgrt_fnameconcat ("", "~/bar", "baz/cde", NULL);
+  if (!out || strcmp (out, "/~/bar/baz/cde"))
+    fail ("fnameconcat failed at line %d (out=%s)\n", __LINE__, out);
+  xfree (out);
+
+  out = gpgrt_fnameconcat ("~/foo", "bar", NULL);
+  if (!out)
+    fail ("fnameconcat failed at line %d\n", __LINE__);
+  else if (home)
+    {
+      if (strlen (out) < homelen + 7)
+        fail ("fnameconcat failed at line %d (out=%s)\n", __LINE__, out);
+      else if (strncmp (out, home, homelen))
+        fail ("fnameconcat failed at line %d (out=%s)\n", __LINE__, out);
+      else if (strcmp (out+homelen, "/foo/bar"))
+        fail ("fnameconcat failed at line %d (out=%s)\n", __LINE__, out);
+    }
+  else
+    {
+      if (strcmp (out, "~/foo/bar"))
+        fail ("fnameconcat failed at line %d (out=%s)\n", __LINE__, out);
+    }
+  xfree (out);
+
+  out = gpgrt_fnameconcat ("~", "bar", NULL);
+  if (!out)
+    fail ("fnameconcat failed at line %d\n", __LINE__);
+  else if (home)
+    {
+      if (strlen (out) < homelen + 3)
+        fail ("fnameconcat failed at line %d (out=%s)\n", __LINE__, out);
+      else if (strncmp (out, home, homelen))
+        fail ("fnameconcat failed at line %d (out=%s)\n", __LINE__, out);
+      else if (strcmp (out+homelen, "/bar"))
+        fail ("fnameconcat failed at line %d (out=%s)\n", __LINE__, out);
+    }
+  else
+    {
+      if (strcmp (out, "~/bar"))
+        fail ("fnameconcat failed at line %d (out=%s)\n", __LINE__, out);
+    }
+  xfree (out);
+}
+
+
+static void
+check_absfnameconcat (void)
+{
+  char *out;
+  char *cwd = mygetcwd ();
+  size_t cwdlen = strlen (cwd);
+
+  out = gpgrt_absfnameconcat ("foo", "bar", NULL);
+  if (!out)
+    fail ("fnameconcat failed at line %d\n", __LINE__);
+  else if (strlen (out) < cwdlen + 7)
+    fail ("fnameconcat failed at line %d (out=%s)\n", __LINE__, out);
+  else if (strncmp (out, cwd, cwdlen))
+    fail ("fnameconcat failed at line %d (out=%s)\n", __LINE__, out);
+  else if (strcmp (out+cwdlen, "/foo/bar"))
+    fail ("fnameconcat failed at line %d (out=%s)\n", __LINE__, out);
+  xfree (out);
+
+  out = gpgrt_absfnameconcat ("./foo", NULL);
+  if (!out)
+    fail ("fnameconcat failed at line %d (out=%s)\n", __LINE__, out);
+  else if (strlen (out) < cwdlen + 5)
+    fail ("fnameconcat failed at line %d (out=%s)\n", __LINE__, out);
+  else if (strncmp (out, cwd, cwdlen))
+    fail ("fnameconcat failed at line %d (out=%s)\n", __LINE__, out);
+  else if (strcmp (out+cwdlen, "/./foo"))
+    fail ("fnameconcat failed at line %d (out=%s)\n", __LINE__, out);
+  xfree (out);
+
+  out = gpgrt_absfnameconcat (".", NULL);
+  if (!out)
+    fail ("fnameconcat failed at line %d\n", __LINE__);
+  else if (strlen (out) < cwdlen)
+    fail ("fnameconcat failed at line %d (out=%s)\n", __LINE__, out);
+  else if (strncmp (out, cwd, cwdlen))
+    fail ("fnameconcat failed at line %d (out=%s)\n", __LINE__, out);
+  else if (strcmp (out+cwdlen, ""))
+    fail ("fnameconcat failed at line %d (out=%s)\n", __LINE__, out);
+  xfree (out);
+
+  xfree (cwd);
+}
+
+
+int
+main (int argc, char **argv)
+{
+  gpgrt_opt_t opts[] = {
+    ARGPARSE_x  ('v', "verbose", NONE, 0, "Print more diagnostics"),
+    ARGPARSE_s_n('d', "debug", "Flyswatter"),
+    ARGPARSE_end()
+  };
+  gpgrt_argparse_t pargs = { &argc, &argv, 0 };
+
+  gpgrt_set_strusage (my_strusage);
+  gpgrt_log_set_prefix (gpgrt_strusage (11), GPGRT_LOG_WITH_PREFIX);
+
+  while (gpgrt_argparse  (NULL, &pargs, opts))
+    {
+      switch (pargs.r_opt)
+        {
+        case 'v': verbose++; break;
+        case 'd': debug++; break;
+        default : pargs.err = ARGPARSE_PRINT_ERROR; break;
+	}
+    }
+  gpgrt_argparse (NULL, &pargs, NULL);
+
+  show ("testing string utilities\n");
+
+  check_fnameconcat ();
+  check_absfnameconcat ();
+
+  show ("testing string utilities finished\n");
+  return !!errorcount;
+}