localedef: Add verbose messages for failure paths.

During testing of localedef running in a minimal container
there were several error cases which were hard to diagnose
since they appeared as strerror (errno) values printed by the
higher level functions.  This change adds three new verbose
messages for potential failure paths.  The new messages give
the user the opportunity to use -v and display additional
information about why localedef might be failing.  I found
these messages useful myself while writing a localedef
container test for --no-hard-links.

Since the changes cleanup the code that handle codeset
normalization we add tst-localedef-path-norm which contains
many sub-tests to verify the correct expected normalization of
codeset strings both when installing to default paths (the
only time normalization is enabled) and installing to absolute
paths.  During the refactoring I created at least one
buffer-overflow which valgrind caught, but these tests did not
catch because the exec in the container had a very clean heap
with zero-initialized memory. However, between valgrind and
the tests the results are clean.

The new tst-localedef-path-norm passes without regression on
x86_64.

Change-Id: I28b9f680711ff00252a2cb15625b774cc58ecb9d

3 files changed, 113 insertions, 73 deletions

diff --git a/locale/programs/localedef.c b/locale/programs/localedef.c
index dbbb0145c0..b048bd05b9 100644
--- a/locale/programs/localedef.c
+++ b/locale/programs/localedef.c
@@ -180,14 +180,14 @@ static struct argp argp =
 
 /* Prototypes for local functions.  */
 static void error_print (void);
-static const char *construct_output_path (char *path);
-static const char *normalize_codeset (const char *codeset, size_t name_len);
+static char *construct_output_path (char *path);
+static char *normalize_codeset (const char *codeset, size_t name_len);
 
 
 int
 main (int argc, char *argv[])
 {
-  const char *output_path;
+  char *output_path;
   int cannot_write_why;
   struct charmap_t *charmap;
   struct localedef_t global;
@@ -232,7 +232,8 @@ main (int argc, char *argv[])
     }
 
   /* The parameter describes the output path of the constructed files.
-     If the described files cannot be written return a NULL pointer.  */
+     If the described files cannot be written return a NULL pointer.
+     We don't free output_path because we will exit.  */
   output_path  = construct_output_path (argv[remaining]);
   if (output_path == NULL && ! no_archive)
     error (4, errno, _("cannot create directory for output files"));
@@ -434,20 +435,16 @@ more_help (int key, const char *text, void *input)
     {
     case ARGP_KEY_HELP_EXTRA:
       /* We print some extra information.  */
-      if (asprintf (&tp, gettext ("\
+      tp = xasprintf (gettext ("\
 For bug reporting instructions, please see:\n\
-%s.\n"), REPORT_BUGS_TO) < 0)
-	return NULL;
-      if (asprintf (&cp, gettext ("\
+%s.\n"), REPORT_BUGS_TO);
+      cp = xasprintf (gettext ("\
 System's directory for character maps : %s\n\
 		       repertoire maps: %s\n\
 		       locale path    : %s\n\
 %s"),
-		    CHARMAP_PATH, REPERTOIREMAP_PATH, LOCALE_PATH, tp) < 0)
-	{
-	  free (tp);
-	  return NULL;
-	}
+		    CHARMAP_PATH, REPERTOIREMAP_PATH, LOCALE_PATH, tp);
+      free (tp);
       return cp;
     default:
       break;
@@ -477,15 +474,13 @@ error_print (void)
 }
 
 
-/* The parameter to localedef describes the output path.  If it does
-   contain a '/' character it is a relative path.  Otherwise it names the
-   locale this definition is for.  */
-static const char *
+/* The parameter to localedef describes the output path.  If it does contain a
+   '/' character it is a relative path.  Otherwise it names the locale this
+   definition is for.   The returned path must be freed by the caller. */
+static char *
 construct_output_path (char *path)
 {
-  const char *normal = NULL;
   char *result;
-  char *endp;
 
   if (strchr (path, '/') == NULL)
     {
@@ -493,50 +488,44 @@ construct_output_path (char *path)
 	 contains a reference to the codeset.  This should be
 	 normalized.  */
       char *startp;
+      char *endp = NULL;
+      char *normal = NULL;
 
       startp = path;
-      /* We must be prepared for finding a CEN name or a location of
-	 the introducing `.' where it is not possible anymore.  */
+      /* Either we have a '@' which starts a CEN name or '.' which starts the
+	 codeset specification.  The CEN name starts with '@' and may also have
+	 a codeset specification, but we do not normalize the string after '@'.
+	 If we only find the codeset specification then we normalize only the codeset
+	 specification (but not anything after a subsequent '@').  */
       while (*startp != '\0' && *startp != '@' && *startp != '.')
 	++startp;
       if (*startp == '.')
 	{
 	  /* We found a codeset specification.  Now find the end.  */
 	  endp = ++startp;
+
+	  /* Stop at the first '@', and don't normalize anything past that.  */
 	  while (*endp != '\0' && *endp != '@')
 	    ++endp;
 
 	  if (endp > startp)
 	    normal = normalize_codeset (startp, endp - startp);
 	}
-      else
-	/* This is to keep gcc quiet.  */
-	endp = NULL;
 
-      /* We put an additional '\0' at the end of the string because at
-	 the end of the function we need another byte for the trailing
-	 '/'.  */
-      ssize_t n;
       if (normal == NULL)
-	n = asprintf (&result, "%s%s/%s%c", output_prefix ?: "",
-		      COMPLOCALEDIR, path, '\0');
+	result = xasprintf ("%s%s/%s/", output_prefix ?: "",
+			    COMPLOCALEDIR, path);
       else
-	n = asprintf (&result, "%s%s/%.*s%s%s%c",
-		      output_prefix ?: "", COMPLOCALEDIR,
-		      (int) (startp - path), path, normal, endp, '\0');
-
-      if (n < 0)
-	return NULL;
-
-      endp = result + n - 1;
+	result = xasprintf ("%s%s/%.*s%s%s/",
+			    output_prefix ?: "", COMPLOCALEDIR,
+			    (int) (startp - path), path, normal, endp ?: "");
+      /* Free the allocated normalized codeset name.  */
+      free (normal);
     }
   else
     {
-      /* This is a user path.  Please note the additional byte in the
-	 memory allocation.  */
-      size_t len = strlen (path) + 1;
-      result = xmalloc (len + 1);
-      endp = mempcpy (result, path, len) - 1;
+      /* This is a user path.  */
+      result = xasprintf ("%s/", path);
 
       /* If the user specified an output path we cannot add the output
 	 to the archive.  */
@@ -546,25 +535,41 @@ construct_output_path (char *path)
   errno = 0;
 
   if (no_archive && euidaccess (result, W_OK) == -1)
-    /* Perhaps the directory does not exist now.  Try to create it.  */
-    if (errno == ENOENT)
-      {
-	errno = 0;
-	if (mkdir (result, 0777) < 0)
-	  return NULL;
-      }
-
-  *endp++ = '/';
-  *endp = '\0';
+    {
+      /* Perhaps the directory does not exist now.  Try to create it.  */
+      if (errno == ENOENT)
+	{
+	  errno = 0;
+	  if (mkdir (result, 0777) < 0)
+	    {
+	      record_verbose (stderr,
+			      _("cannot create output path \'%s\': %s"),
+			      result, strerror (errno));
+	      free (result);
+	      return NULL;
+	    }
+	}
+      else
+	record_verbose (stderr,
+			_("no write permission to output path \'%s\': %s"),
+			result, strerror (errno));
+    }
 
   return result;
 }
 
 
-/* Normalize codeset name.  There is no standard for the codeset
-   names.  Normalization allows the user to use any of the common
-   names.  */
-static const char *
+/* Normalize codeset name.  There is no standard for the codeset names.
+   Normalization allows the user to use any of the common names e.g. UTF-8,
+   utf-8, utf8, UTF8 etc.
+
+   We normalize using the following rules:
+   - Remove all non-alpha-numeric characters
+   - Lowercase all characters.
+   - If there are only digits assume it's an ISO standard and prefix with 'iso'
+
+   We return the normalized string which needs to be freed by free.  */
+static char *
 normalize_codeset (const char *codeset, size_t name_len)
 {
   int len = 0;
@@ -573,6 +578,7 @@ normalize_codeset (const char *codeset, size_t name_len)
   char *wp;
   size_t cnt;
 
+  /* Compute the length of only the alpha-numeric characters.  */
   for (cnt = 0; cnt < name_len; ++cnt)
     if (isalnum (codeset[cnt]))
       {
@@ -582,25 +588,24 @@ normalize_codeset (const char *codeset, size_t name_len)
 	  only_digit = 0;
       }
 
-  retval = (char *) malloc ((only_digit ? 3 : 0) + len + 1);
+  /* If there were only digits we assume it's an ISO standard and we will
+     prefix with 'iso' so include space for that.  We fill in the required
+     space from codeset up to the converted length.  */
+  wp = retval = xasprintf ("%s%.*s", only_digit ? "iso" : "", len, codeset);
 
-  if (retval != NULL)
-    {
-      if (only_digit)
-	wp = stpcpy (retval, "iso");
-      else
-	wp = retval;
-
-      for (cnt = 0; cnt < name_len; ++cnt)
-	if (isalpha (codeset[cnt]))
-	  *wp++ = tolower (codeset[cnt]);
-	else if (isdigit (codeset[cnt]))
-	  *wp++ = codeset[cnt];
+  /* Skip "iso".  */
+  if (only_digit)
+    wp += 3;
 
-      *wp = '\0';
-    }
+  /* Lowercase all characters. */
+  for (cnt = 0; cnt < name_len; ++cnt)
+    if (isalpha (codeset[cnt]))
+      *wp++ = tolower (codeset[cnt]);
+    else if (isdigit (codeset[cnt]))
+      *wp++ = codeset[cnt];
 
-  return (const char *) retval;
+  /* Return allocated and converted name for caller to free.  */
+  return retval;
 }
 
 
diff --git a/locale/programs/localedef.h b/locale/programs/localedef.h
index 62ad717216..c98acf1bbe 100644
--- a/locale/programs/localedef.h
+++ b/locale/programs/localedef.h
@@ -123,6 +123,7 @@ extern bool hard_links;
 
 /* Prototypes for a few program-wide used functions.  */
 #include <programs/xmalloc.h>
+#include <programs/xasprintf.h>
 
 
 /* Mark given locale as to be read.  */
diff --git a/locale/programs/xasprintf.c b/locale/programs/xasprintf.c
new file mode 100644
index 0000000000..efc91a9c34
--- /dev/null
+++ b/locale/programs/xasprintf.c
@@ -0,0 +1,34 @@
+/* asprintf with out of memory checking
+   Copyright (C) 2019 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   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; version 2 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/>.  */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdarg.h>
+#include <libintl.h>
+#include <error.h>
+
+char *
+xasprintf (const char *format, ...)
+{
+  va_list ap;
+  va_start (ap, format);
+  char *result;
+  if (vasprintf (&result, format, ap) < 0)
+    error (EXIT_FAILURE, 0, _("memory exhausted"));
+  va_end (ap);
+  return result;
+}