libdpkg: Refactor path basename code into new path_basename function

This function is an equivalent of the GNU basename, but this one will
work consistently on any system regardless of libc used.

dpkg-split/split.c

@@ -3,7 +3,7 @@
  * split.c - splitting archives
  *
  * Copyright © 1995 Ian Jackson <ian@chiark.greenend.org.uk>
- * Copyright © 2010 Guillem Jover <guillem@debian.org>
+ * Copyright © 2008-2011 Guillem Jover <guillem@debian.org>
  *
  * This is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -40,6 +40,7 @@
 #include <dpkg/i18n.h>
 #include <dpkg/dpkg.h>
 #include <dpkg/dpkg-db.h>
+#include <dpkg/path.h>
 #include <dpkg/subproc.h>
 #include <dpkg/buffer.h>
 #include <dpkg/ar.h>
@@ -160,10 +161,7 @@ mksplit(const char *file_src, const char *prefix, off_t maxpartsize,
 		prefixdir = m_strdup(dirname(t));
 		free(t);
 
-		t = m_strdup(prefix);
-		msdos_prefix = m_strdup(basename(t));
-		free(t);
-
+		msdos_prefix = m_strdup(path_basename(prefix));
 		prefix = clean_msdos_filename(msdos_prefix);
 	}
 

lib/dpkg/command.c

@@ -2,7 +2,7 @@
  * libdpkg - Debian packaging suite library routines
  * command.c - command execution support
  *
- * Copyright © 2010 Guillem Jover <guillem@debian.org>
+ * Copyright © 2010-2011 Guillem Jover <guillem@debian.org>
  *
  * This is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -27,6 +27,7 @@
 
 #include <dpkg/dpkg.h>
 #include <dpkg/i18n.h>
+#include <dpkg/path.h>
 #include <dpkg/command.h>
 
 /**
@@ -43,11 +44,9 @@ void
 command_init(struct command *cmd, const char *filename, const char *name)
 {
 	cmd->filename = filename;
-	if (name == NULL) {
-		const char *progname = strrchr(filename, '/');
-
-		cmd->name = progname ? progname + 1 : filename;
-	} else
+	if (name == NULL)
+		cmd->name = path_basename(filename);
+	else
 		cmd->name = name;
 	cmd->argc = 0;
 	cmd->argv_size = 10;

lib/dpkg/path.c

@@ -3,7 +3,7 @@
  * path.c - path handling functions
  *
  * Copyright © 1995 Ian Jackson <ian@chiark.greenend.org.uk>
- * Copyright © 2008-2010 Guillem Jover <guillem@debian.org>
+ * Copyright © 2008-2011 Guillem Jover <guillem@debian.org>
  *
  * This is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -72,6 +72,25 @@ path_skip_slash_dotslash(const char *path)
 	return path;
 }
 
+/**
+ * Return the last component of a pathname.
+ *
+ * @param path The pathname to get the base name from.
+ *
+ * @return A pointer to the last component inside pathname.
+ */
+const char *
+path_basename(const char *path)
+{
+	const char *last_slash;
+
+	last_slash = strrchr(path, '/');
+	if (last_slash == NULL)
+		return path;
+	else
+		return last_slash + 1;
+}
+
 /**
  * Create a template for a temporary pathname.
  *

lib/dpkg/path.h

@@ -2,7 +2,7 @@
  * libdpkg - Debian packaging suite library routines
  * path.h - path handling routines
  *
- * Copyright © 2008, 2009 Guillem Jover <guillem@debian.org>
+ * Copyright © 2008-2011 Guillem Jover <guillem@debian.org>
  *
  * This is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -29,6 +29,7 @@ DPKG_BEGIN_DECLS
 
 size_t path_trim_slash_slashdot(char *path);
 const char *path_skip_slash_dotslash(const char *path);
+const char *path_basename(const char *path);
 char *path_quote_filename(char *dst, const char *src, size_t size);
 
 char *path_make_temp_template(const char *suffix);

lib/dpkg/progname.c

@@ -22,9 +22,9 @@
 #include <compat.h>
 
 #include <errno.h>
-#include <string.h>
 #include <stdlib.h>
 
+#include <dpkg/path.h>
 #include <dpkg/progname.h>
 
 static const char *progname;
@@ -40,13 +40,7 @@ static const char *progname;
 void
 dpkg_set_progname(const char *name)
 {
-	const char *last_slash;
-
-	last_slash = strrchr(name, '/');
-	if (last_slash == NULL)
-		progname = name;
-	else
-		progname = last_slash + 1;
+	progname = path_basename(name);
 }
 
 #if defined(HAVE___PROGNAME)

lib/dpkg/test/t-path.c

@@ -73,6 +73,18 @@ test_path_skip(void)
 	test_str(path_skip_slash_dotslash("/./foo/bar/./"), ==, "foo/bar/./");
 }
 
+static void
+test_path_basename(void)
+{
+	test_str(path_basename("./."), ==, ".");
+	test_str(path_basename("./"), ==, "");
+	test_str(path_basename("/."), ==, ".");
+	test_str(path_basename("/"), ==, "");
+	test_str(path_basename("/foo"), ==, "foo");
+	test_str(path_basename("/foo/bar"), ==, "bar");
+	test_str(path_basename("/foo/bar/"), ==, "");
+}
+
 static void
 test_path_temp(void)
 {
@@ -162,6 +174,7 @@ test(void)
 {
 	test_path_trim();
 	test_path_skip();
+	test_path_basename();
 	test_path_temp();
 	test_path_quote();
 }

src/configure.c

@@ -45,6 +45,7 @@
 #include <dpkg/string.h>
 #include <dpkg/buffer.h>
 #include <dpkg/file.h>
+#include <dpkg/path.h>
 #include <dpkg/subproc.h>
 #include <dpkg/command.h>
 #include <dpkg/triglib.h>
@@ -659,9 +660,7 @@ promptconfaction(struct pkginfo *pkg, const char *cfgfile,
 		else if (what & cfof_install)
 			fprintf(stderr, _(" The default action is to install the new version.\n"));
 
-		s = strrchr(cfgfile, '/');
-		if (!s || !*++s)
-			s = cfgfile;
+		s = path_basename(cfgfile);
 		fprintf(stderr, "*** %s (Y/I/N/O/D/Z) %s ? ",
 		        s,
 		        (what & cfof_keep) ? _("[default=N]") :