# HG changeset patch
# User J. Ali Harlow <ali@juiblex.co.uk>
# Date 1329004226 0
# Node ID 6112bcc5d1cffd683369a263ab0e53668815d781
# Parent  6fa783097ca1dc7bc9931582ff3a467281d20f72
Add an error object.
This is intended to dis-entangle the two roles that the atomic
object has evolved into so that atomic need only be used where
atomic actions are actually being undertaken.

diff -r 6fa783097ca1 -r 6112bcc5d1cf configure.ac
--- a/configure.ac	Sat Feb 11 09:49:58 2012 +0000
+++ b/configure.ac	Sat Feb 11 23:50:26 2012 +0000
@@ -10,9 +10,9 @@
 #
 # See http://sources.redhat.com/autobook/autobook/autobook_91.html#SEC91 for details
 #
-LT_CURRENT=3
+LT_CURRENT=4
 LT_REVISION=0
-LT_AGE=1
+LT_AGE=2
 AC_SUBST(LT_CURRENT)
 AC_SUBST(LT_REVISION)
 AC_SUBST(LT_AGE)
diff -r 6fa783097ca1 -r 6112bcc5d1cf librazor/Makefile.am
--- a/librazor/Makefile.am	Sat Feb 11 09:49:58 2012 +0000
+++ b/librazor/Makefile.am	Sat Feb 11 23:50:26 2012 +0000
@@ -33,6 +33,7 @@
 	iterator.c					\
 	importer.c					\
 	merger.c					\
+	error.c						\
 	atomic.c					\
 	atomic-ktm.c					\
 	atomic-none.c					\
diff -r 6fa783097ca1 -r 6112bcc5d1cf librazor/atomic-actions.c
--- a/librazor/atomic-actions.c	Sat Feb 11 09:49:58 2012 +0000
+++ b/librazor/atomic-actions.c	Sat Feb 11 23:50:26 2012 +0000
@@ -259,9 +259,9 @@
 		return 0;
 
 	if (errno != EEXIST || chmod(action->args.path, mode) < 0) {
-		if (!atomic->error_str)
-			razor_atomic_set_error_str(atomic, action->args.path,
-						   strerror(errno));
+		if (!atomic->error)
+			atomic->error = razor_error_new_str(action->args.path,
+							    strerror(errno));
 		atomic_action_free(action);
 		return NULL;
 	}
@@ -278,9 +278,9 @@
 	}
 
 	if (rmdir(action->args.path) < 0) {
-		if (!atomic->error_str)
-			razor_atomic_set_error_str(atomic, action->args.path,
-						   strerror(errno));
+		if (!atomic->error)
+			atomic->error = razor_error_new_str(action->args.path,
+							    strerror(errno));
 		atomic_action_free(action);
 		return NULL;
 	} else
@@ -301,9 +301,9 @@
 
 	r = symlink(action->args.u.create_symlink.target, action->args.path);
 	if (r < 0) {
-		if (!atomic->error_str)
-			razor_atomic_set_error_str(atomic, NULL,
-						   strerror(errno));
+		if (!atomic->error)
+			atomic->error = razor_error_new_str(action->args.path,
+							    strerror(errno));
 		atomic_action_free(action);
 		return NULL;
 	}
@@ -321,9 +321,9 @@
 	}
 
 	if (unlink(action->args.path) < 0) {
-		if (!atomic->error_str)
-			razor_atomic_set_error_str(atomic, NULL,
-						   strerror(errno));
+		if (!atomic->error)
+			atomic->error = razor_error_new_str(action->args.path,
+							    strerror(errno));
 		atomic_action_free(action);
 		return NULL;
 	}
@@ -351,9 +351,9 @@
 	(void)RemoveDirectoryW(newbuf);
 
 	if (!MoveFileExW(oldbuf, newbuf, flags)) {
-		if (!atomic->error_str)
-			razor_atomic_set_error_mswin(atomic, newbuf,
-						     GetLastError());
+		if (!atomic->error)
+			atomic->error = razor_error_new_mswin(newbuf,
+							      GetLastError());
 		return -1;
 	}
 
@@ -361,9 +361,9 @@
 	free(oldbuf);
 #else
 	if (rename(path, dest)) {
-		if (!atomic->error_str)
-			razor_atomic_set_error_str(atomic, dest,
-						   strerror(errno));
+		if (!atomic->error)
+			atomic->error = razor_error_new_str(dest,
+							    strerror(errno));
 		return -1;
 	}
 #endif
diff -r 6fa783097ca1 -r 6112bcc5d1cf librazor/atomic-emulate.c
--- a/librazor/atomic-emulate.c	Sat Feb 11 09:49:58 2012 +0000
+++ b/librazor/atomic-emulate.c	Sat Feb 11 23:50:26 2012 +0000
@@ -21,6 +21,7 @@
 #if ENABLE_ATOMIC && !HAVE_WINDOWS_KTM
 
 #include <stdlib.h>
+#include <stdio.h>
 #include <string.h>
 #include <unistd.h>
 #include <sys/types.h>
@@ -108,7 +109,7 @@
 		atomic->toplevel = NULL;
 	}
 
-	return !!atomic->error_str;
+	return razor_atomic_in_error_state(atomic);
 }
 
 RAZOR_EXPORT void razor_atomic_destroy(struct razor_atomic *atomic)
@@ -119,9 +120,9 @@
 		atomic->toplevel = NULL;
 	}
 
-	free(atomic->error_path);
-	free(atomic->error_str);
-	free(atomic->error_msg);
+	if (atomic->error)
+		razor_error_free(atomic->error);
+
 	free(atomic);
 }
 
@@ -210,8 +211,9 @@
 
 	return 0;
 #else
-	razor_atomic_set_error_str(atomic, NULL, "Symbolic links not supported "
-						 "on this platform");
+	atomic->error = razor_error_new_str(NULL,
+					    "Symbolic links not supported "
+					    "on this platform");
 
 	return -1;
 #endif
@@ -228,13 +230,12 @@
 	if (razor_atomic_in_error_state(atomic))
 		return -1;
 
-	atomic->error_path = strdup(filename);
 	tmpnam = atomic_action_attic_tmpnam(atomic);
 	fd = open(tmpnam, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY,
 		  mode & (S_IRWXU | S_IRWXG | S_IRWXO));
 
 	if (fd == -1)
-		razor_atomic_set_error_str(atomic, NULL, strerror(errno));
+		atomic->error = razor_error_new_str(filename, strerror(errno));
 	else {
 		a = atomic_action_new(ACTION_MOVE);
 		a->args.path = tmpnam;
diff -r 6fa783097ca1 -r 6112bcc5d1cf librazor/atomic-ktm.c
--- a/librazor/atomic-ktm.c	Sat Feb 11 09:49:58 2012 +0000
+++ b/librazor/atomic-ktm.c	Sat Feb 11 23:50:26 2012 +0000
@@ -131,45 +131,6 @@
 	return atomic;
 }
 
-void
-razor_atomic_set_error_str(struct razor_atomic *atomic, const wchar_t *path,
-			   const char *str)
-{
-	assert(!atomic->error_str);
-
-	free(atomic->error_path);
-
-	if (path)
-		atomic->error_path = razor_utf16_to_utf8(path, -1);
-	else
-		atomic->error_path = NULL;
-
-	atomic->error_str = strdup(str);
-}
-
-static void
-razor_atomic_set_error(struct razor_atomic *atomic, const wchar_t *path,
-		       DWORD error)
-{
-	wchar_t *buf;
-
-	assert(!atomic->error_str);
-
-	free(atomic->error_path);
-
-	if (path)
-		atomic->error_path = razor_utf16_to_utf8(path, -1);
-	else
-		atomic->error_path = NULL;
-
-	FormatMessageW(FORMAT_MESSAGE_ALLOCATE_BUFFER|
-		       FORMAT_MESSAGE_FROM_SYSTEM|FORMAT_MESSAGE_IGNORE_INSERTS,
-		       NULL, error, MAKELANGID(LANG_NEUTRAL,SUBLANG_DEFAULT),
-		       (LPWSTR)&buf, 0, NULL);
-	atomic->error_str = razor_utf16_to_utf8(buf, -1);
-	LocalFree(buf);
-}
-
 RAZOR_EXPORT int
 razor_atomic_commit(struct razor_atomic *atomic)
 {
@@ -181,7 +142,7 @@
 	retval = !CommitTransaction(atomic->transaction);
 
 	if (retval) {
-		razor_atomic_set_error(atomic, NULL, GetLastError());
+		atomic->error = razor_error_new_mswin(NULL, GetLastError());
 		RollbackTransaction(atomic->transaction);
 	}
 
@@ -207,9 +168,8 @@
 		RollbackTransaction(atomic->transaction);
 		CloseHandle(atomic->transaction);
 	}
-	free(atomic->error_path);
-	free(atomic->error_str);
-	free(atomic->error_msg);
+	if (atomic->error)
+		razor_error_free(atomic->error);
 	free(atomic);
 }
 
@@ -250,16 +210,15 @@
 				if (err == ERROR_FILE_NOT_FOUND) {
 					creating = 1;
 				} else {
-					razor_atomic_set_error(atomic,
-							       buffer->str,
-							       err);
+					atomic->error = razor_error_new_mswin(buffer->str,
+									      err);
 					razor_wstr_destroy(buffer);
 					return -1;
 				}
 			} else if (!(fa.dwFileAttributes&
 				     FILE_ATTRIBUTE_DIRECTORY)) {
-				razor_atomic_set_error_str(atomic, buffer->str,
-							   "Not a directory");
+				atomic->error = razor_error_new_str(buffer->str,
+								    "Not a directory");
 				razor_wstr_destroy(buffer);
 				return -1;
 			}
@@ -267,8 +226,8 @@
 		if (creating) {
 			if (!CreateDirectoryTransactedW(NULL, buffer->str, NULL,
 							atomic->transaction)) {
-				razor_atomic_set_error(atomic, buffer->str,
-						       GetLastError());
+				atomic->error = razor_error_new_mswin(buffer->str,
+								      GetLastError());
 				razor_wstr_destroy(buffer);
 				return -1;
 			}
@@ -328,7 +287,7 @@
 	 * same path, this is likely to cause more problems than it solves.
 	 */
 
-	razor_atomic_set_error(atomic, buf, err);
+	atomic->error = razor_error_new_mswin(buf, err);
 	free(buf);
 	return -1;
 }
@@ -356,12 +315,12 @@
 
 	if (!MoveFileTransactedW(oldbuf, newbuf, NULL, NULL, flags,
 			         atomic->transaction))
-		razor_atomic_set_error(atomic, newbuf, GetLastError());
+		atomic->error = razor_error_new_mswin(newbuf, GetLastError());
 
 	free(newbuf);
 	free(oldbuf);
 
-	return !!atomic->error_str;
+	return razor_atomic_in_error_state(atomic);
 }
 
 RAZOR_EXPORT int
@@ -381,7 +340,7 @@
 		err = GetLastError();
 		if (err != ERROR_FILE_EXISTS && err != ERROR_ALREADY_EXISTS) {
 abort:
-			razor_atomic_set_error(atomic, buf, err);
+			atomic->error = razor_error_new_mswin(buf, err);
 			free(buf);
 			return -1;
 		}
@@ -421,8 +380,9 @@
 	 * and we don't always know that at the time when the
 	 * link is created, so it's a convienent lie for now.
 	 */
-	razor_atomic_set_error_str(atomic, NULL, "Symbolic links not supported "
-						 "on this platform");
+	atomic->error = razor_error_new_str(NULL,
+					    "Symbolic links not supported "
+					    "on this platform");
 
 	return -1;
 }
@@ -441,7 +401,7 @@
 	files = realloc(atomic->files,
 			(atomic->n_files+1) * sizeof(struct razor_atomic_file));
 	if (!files) {
-		razor_atomic_set_error_str(atomic, NULL, "Not enough memory");
+		atomic->error = razor_error_new_str(NULL, "Not enough memory");
 		return -1;
 	}
 	atomic->n_files++;
@@ -468,7 +428,8 @@
 					   NULL);
 
 	if (files[i].h == INVALID_HANDLE_VALUE) {
-		razor_atomic_set_error(atomic, files[i].path, GetLastError());
+		atomic->error = razor_error_new_mswin(files[i].path,
+						      GetLastError());
 		free(files[i].path);
 		atomic->n_files--;
 		return -1;
@@ -492,9 +453,8 @@
 	while(size) {
 		if (!WriteFile(atomic->files[handle].h, data, size, &written,
 			       NULL)) {
-			razor_atomic_set_error(atomic,
-					       atomic->files[handle].path,
-					       GetLastError());
+			atomic->error = razor_error_new_mswin(atomic->files[handle].path,
+							      GetLastError());
 
 			(void)CloseHandle(atomic->files[handle].h);
 			free(atomic->files[handle].path);
@@ -523,8 +483,8 @@
 	assert(atomic->files[handle].h != INVALID_HANDLE_VALUE);
 
 	if (!CloseHandle(atomic->files[handle].h)) {
-		razor_atomic_set_error(atomic, atomic->files[handle].path,
-				       GetLastError());
+		atomic->error = razor_error_new_mswin(atomic->files[handle].path,
+						      GetLastError());
 		free(atomic->files[handle].path);
 		atomic->files[handle].path = NULL;
 		atomic->files[handle].h = INVALID_HANDLE_VALUE;
@@ -537,14 +497,14 @@
 	atomic->files[handle].h = h;
 
 	if (atomic->files[handle].h == INVALID_HANDLE_VALUE) {
-		razor_atomic_set_error(atomic, atomic->files[handle].path,
-				       GetLastError());
+		atomic->error = razor_error_new_mswin(atomic->files[handle].path,
+						      GetLastError());
 		free(atomic->files[handle].path);
 		atomic->files[handle].path = NULL;
 		return -1;
 	}
 
-	return !!atomic->error_str;
+	return razor_atomic_in_error_state(atomic);
 }
 
 RAZOR_EXPORT int
@@ -557,8 +517,8 @@
 	assert(atomic->files[handle].h != INVALID_HANDLE_VALUE);
 
 	if (!CloseHandle(atomic->files[handle].h))
-		razor_atomic_set_error(atomic, atomic->files[handle].path,
-				       GetLastError());
+		atomic->error = razor_error_new_mswin(atomic->files[handle].path,
+						      GetLastError());
 
 	free(atomic->files[handle].path);
 	atomic->files[handle].path = NULL;
@@ -568,7 +528,7 @@
 	      atomic->files[atomic->n_files-1].h == INVALID_HANDLE_VALUE)
 		atomic->n_files--;
 
-	return !!atomic->error_str;
+	return razor_atomic_in_error_state(atomic);
 }
 
 #endif		/* HAVE_WINDOWS_KTM */
diff -r 6fa783097ca1 -r 6112bcc5d1cf librazor/atomic-none.c
--- a/librazor/atomic-none.c	Sat Feb 11 09:49:58 2012 +0000
+++ b/librazor/atomic-none.c	Sat Feb 11 23:50:26 2012 +0000
@@ -59,9 +59,9 @@
 RAZOR_EXPORT void
 razor_atomic_destroy(struct razor_atomic *atomic)
 {
-	free(atomic->error_path);
-	free(atomic->error_str);
-	free(atomic->error_msg);
+	if (atomic->error)
+		razor_error_free(atomic->error);
+
 	free(atomic);
 }
 
@@ -97,13 +97,13 @@
 
 		if (stat(buffer, &buf) == 0) {
 			if (!S_ISDIR(buf.st_mode)) {
-				razor_atomic_set_error_str(atomic, buffer,
-							   "Not a directory");
+				atomic->error = razor_error_new_str(buffer,
+								    "Not a directory");
 				return -1;
 			}
 		} else if (mkdir(buffer, 0777) < 0) {
-			razor_atomic_set_error_str(atomic, buffer,
-						   strerror(errno));
+			atomic->error = razor_error_new_str(buffer,
+							    strerror(errno));
 			return -1;
 		}
 	}
@@ -133,16 +133,16 @@
 		      DeleteFileW(buf)) &&
 		    !RemoveDirectoryW(buf) &&
 		    GetLastError() != ERROR_DIR_NOT_EMPTY)
-			razor_atomic_set_error_mswin(atomic, buf, err);
+			atomic->error = razor_error_new_mswin(buf, err);
 	}
 
 	free(buf);
 #else
 	if (remove(path))
-		razor_atomic_set_error_str(atomic, path, strerror(errno));
+		atomic->error = razor_error_new_str(path, strerror(errno));
 #endif
 
-	return !!atomic->error_str;
+	return razor_atomic_in_error_state(atomic);
 }
 
 RAZOR_EXPORT int
@@ -170,16 +170,16 @@
 	(void)RemoveDirectoryW(newbuf);
 
 	if (!MoveFileExW(oldbuf, newbuf, flags))
-		razor_atomic_set_error_mswin(atomic, newbuf, GetLastError());
+		atomic->error = razor_error_new_mswin(newbuf, GetLastError());
 
 	free(newbuf);
 	free(oldbuf);
 #else
 	if (rename(oldpath, newpath))
-		razor_atomic_set_error_str(atomic, newpath, strerror(errno));
+		atomic->error = razor_error_new_str(newpath, strerror(errno));
 #endif
 
-	return !!atomic->error_str;
+	return razor_atomic_in_error_state(atomic);
 }
 
 RAZOR_EXPORT int
@@ -193,12 +193,12 @@
 		return 0;
 
 	if (errno != EEXIST) {
-		razor_atomic_set_error_str(atomic, dirname, strerror(errno));
+		atomic->error = razor_error_new_str(dirname, strerror(errno));
 		return -1;
 	}
 
 	if (chmod(dirname, mode & (S_IRWXU | S_IRWXG | S_IRWXO)) < 0) {
-		razor_atomic_set_error_str(atomic, dirname, strerror(errno));
+		atomic->error = razor_error_new_str(dirname, strerror(errno));
 		return -1;
 	}
 
@@ -214,14 +214,15 @@
 
 #if HAVE_SYMLINK
 	if (symlink(target, path) < 0) {
-		razor_atomic_set_error_str(atomic, NULL, strerror(errno));
+		atomic->error = razor_error_new_str(path, strerror(errno));
 		return -1;
 	}
 
 	return 0;
 #else
-	razor_atomic_set_error_str(atomic, NULL, "Symbolic links not supported "
-						 "on this platform");
+	atomic->error = razor_error_new_str(NULL,
+					    "Symbolic links not supported "
+					    "on this platform");
 
 	return -1;
 #endif
@@ -236,12 +237,11 @@
 	if (razor_atomic_in_error_state(atomic))
 		return -1;
 
-	atomic->error_path = strdup(filename);
-	fd = open(atomic->error_path, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY,
+	fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY,
 		  mode & (S_IRWXU | S_IRWXG | S_IRWXO));
 
 	if (fd == -1)
-		razor_atomic_set_error_str(atomic, NULL, strerror(errno));
+		atomic->error = razor_error_new_str(filename, strerror(errno));
 
 	return fd;
 }
diff -r 6fa783097ca1 -r 6112bcc5d1cf librazor/atomic.c
--- a/librazor/atomic.c	Sat Feb 11 09:49:58 2012 +0000
+++ b/librazor/atomic.c	Sat Feb 11 23:50:26 2012 +0000
@@ -56,30 +56,23 @@
 RAZOR_EXPORT const char *
 razor_atomic_get_error_msg(struct razor_atomic *atomic)
 {
-	if (!atomic->error_msg) {
-		if (atomic->error_path)
-			atomic->error_msg = razor_concat(atomic->error_path,
-							 ": ",
-							 atomic->error_str,
-							 NULL);
-		else
-			atomic->error_msg = strdup(atomic->error_str);
-	}
-
-	return atomic->error_msg;
+	if (atomic->error)
+		return razor_error_get_msg(atomic->error);
+	else
+		return NULL;
 }
 
 RAZOR_EXPORT void
 razor_atomic_abort(struct razor_atomic *atomic, const char *error_msg)
 {
-	if (!atomic->error_str)
-		razor_atomic_set_error_str(atomic, NULL, error_msg);
+	if (!atomic->error)
+		atomic->error = razor_error_new_str(NULL, error_msg);
 }
 
 RAZOR_EXPORT int
 razor_atomic_in_error_state(struct razor_atomic *atomic)
 {
-	return atomic->error_str && !atomic->in_undo;
+	return atomic->error && !atomic->in_undo;
 }
 
 #if !HAVE_WINDOWS_KTM
@@ -110,41 +103,6 @@
 #endif
 }
 
-#ifdef MSWIN_API
-void
-razor_atomic_set_error_mswin(struct razor_atomic *atomic, const wchar_t *path,
-			     DWORD error)
-{
-	wchar_t *buf;
-
-	assert(!atomic->error_str);
-
-	free(atomic->error_path);
-
-	if (path)
-		atomic->error_path = razor_utf16_to_utf8(path, -1);
-	else
-		atomic->error_path = NULL;
-
-	FormatMessageW(FORMAT_MESSAGE_ALLOCATE_BUFFER|
-		       FORMAT_MESSAGE_FROM_SYSTEM|FORMAT_MESSAGE_IGNORE_INSERTS,
-		       NULL, error, MAKELANGID(LANG_NEUTRAL,SUBLANG_DEFAULT),
-		       (LPWSTR)&buf, 0, NULL);
-	atomic->error_str = razor_utf16_to_utf8(buf, -1);
-	LocalFree(buf);
-}
-#endif
-
-void
-razor_atomic_set_error_str(struct razor_atomic *atomic, const char *path,
-			   const char *str)
-{
-	assert(!atomic->error_str);
-
-	atomic->error_path = path ? strdup(path) : NULL;
-	atomic->error_str = strdup(str);
-}
-
 RAZOR_EXPORT int
 razor_atomic_write(struct razor_atomic *atomic, int fd, const void *data,
 		   size_t size)
@@ -157,8 +115,8 @@
 	while(size) {
 		written = write(fd, data, size);
 		if (written < 0) {
-			razor_atomic_set_error_str(atomic, NULL,
-						   strerror(errno));
+			atomic->error = razor_error_new_str(NULL,
+							    strerror(errno));
 
 			(void)close(fd);
 
@@ -179,13 +137,10 @@
 		return -1;
 
 	if (fsync(handle) < 0) {
-		razor_atomic_set_error_str(atomic, NULL, strerror(errno));
+		atomic->error = razor_error_new_str(NULL, strerror(errno));
 		return -1;
 	}
 
-	free(atomic->error_path);
-	atomic->error_path = NULL;
-
 	return 0;
 }
 
@@ -196,13 +151,10 @@
 		return -1;
 
 	if (close(fd) < 0) {
-		razor_atomic_set_error_str(atomic, NULL, strerror(errno));
+		atomic->error = razor_error_new_str(NULL, strerror(errno));
 		return -1;
 	}
 
-	free(atomic->error_path);
-	atomic->error_path = NULL;
-
 	return 0;
 }
 
diff -r 6fa783097ca1 -r 6112bcc5d1cf librazor/error.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/librazor/error.c	Sat Feb 11 23:50:26 2012 +0000
@@ -0,0 +1,98 @@
+/*
+ * Copyright (C) 2011-2012  J. Ali Harlow <ali@juiblex.co.uk>
+ *
+ * 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 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, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "config.h"
+
+#ifdef MSWIN_API
+#include <windows.h>
+#endif
+#include <stdlib.h>
+#include <string.h>
+
+#include "razor.h"
+#include "razor-internal.h"
+
+RAZOR_EXPORT const char *
+razor_error_get_msg(struct razor_error *error)
+{
+	if (!error->msg) {
+		if (error->path)
+			error->msg = razor_concat(error->path, ": ", error->str,
+						  NULL);
+		else
+			error->msg = strdup(error->str);
+	}
+
+	return error->msg;
+}
+
+#ifdef MSWIN_API
+struct razor_error *
+razor_error_new_mswin(const wchar_t *path, DWORD err)
+{
+	struct razor_error *error;
+	wchar_t *buf;
+
+	error = zalloc(sizeof *error);
+
+	if (path)
+		error->path = razor_utf16_to_utf8(path, -1);
+
+	FormatMessageW(FORMAT_MESSAGE_ALLOCATE_BUFFER|
+		       FORMAT_MESSAGE_FROM_SYSTEM|FORMAT_MESSAGE_IGNORE_INSERTS,
+		       NULL, err, MAKELANGID(LANG_NEUTRAL,SUBLANG_DEFAULT),
+		       (LPWSTR)&buf, 0, NULL);
+	error->str = razor_utf16_to_utf8(buf, -1);
+	LocalFree(buf);
+
+	return error;
+}
+#endif
+
+#if HAVE_WINDOWS_KTM
+struct razor_error *
+razor_error_new_str(const wchar_t *path, const char *str)
+#else
+struct razor_error *
+razor_error_new_str(const char *path, const char *str)
+#endif
+{
+	struct razor_error *error;
+
+	error = zalloc(sizeof *error);
+
+#if HAVE_WINDOWS_KTM
+	if (path)
+		error->path = razor_utf16_to_utf8(path, -1);
+#else
+	if (path)
+		error->path = strdup(path);
+#endif
+
+	error->str = strdup(str);
+
+	return error;
+}
+
+void razor_error_free(struct razor_error *error)
+{
+    free(error->path);
+    free(error->str);
+    free(error->msg);
+    free(error);
+}
diff -r 6fa783097ca1 -r 6112bcc5d1cf librazor/razor-internal.h
--- a/librazor/razor-internal.h	Sat Feb 11 09:49:58 2012 +0000
+++ b/librazor/razor-internal.h	Sat Feb 11 23:50:26 2012 +0000
@@ -242,6 +242,23 @@
 wchar_t *razor_utf8_to_utf16(const char *utf8, int len);
 #endif
 
+/* Error functions */
+struct razor_error {
+	char *path;
+	char *str;
+	char *msg;
+};
+
+#ifdef MSWIN_API
+struct razor_error *razor_error_new_mswin(const wchar_t *path, DWORD error);
+#endif
+
+#if HAVE_WINDOWS_KTM
+struct razor_error *razor_error_new_str(const wchar_t *path, const char *str);
+#else
+struct razor_error *razor_error_new_str(const char *path, const char *str);
+#endif
+
 /* Atomic functions */
 
 #if HAVE_WINDOWS_KTM
@@ -253,9 +270,7 @@
 		HANDLE h;
 	} *files;
 	int in_undo;
-	char *error_path;
-	char *error_str;
-	char *error_msg;
+	struct razor_error *error;
 };
 #elif ENABLE_ATOMIC
 struct atomic_action {
@@ -298,9 +313,7 @@
 	char *toplevel;
 	unsigned next_file_tag;
 	int in_undo;
-	char *error_path;
-	char *error_str;
-	char *error_msg;
+	struct razor_error *error;
 };
 
 char *atomic_action_attic_tmpnam(struct razor_atomic *atomic);
@@ -317,29 +330,11 @@
 #else	/* !HAVE_WINDOWS_KTM && !ENABLE_ATOMIC */
 struct razor_atomic {
 	int in_undo;
-	char *error_path;
-	char *error_str;
-	char *error_msg;
+	struct razor_error *error;
 };
 #endif
 
 int razor_allow_all_root_names(void);
 int razor_valid_root_name(const char *name);
 
-#ifdef MSWIN_API
-void
-razor_atomic_set_error_mswin(struct razor_atomic *atomic, const wchar_t *path,
-			     DWORD error);
-#endif
-
-#if HAVE_WINDOWS_KTM
-void
-razor_atomic_set_error_str(struct razor_atomic *atomic, const wchar_t *path,
-			   const char *str);
-#else
-void
-razor_atomic_set_error_str(struct razor_atomic *atomic, const char *path,
-			   const char *str);
-#endif
-
 #endif /* _RAZOR_INTERNAL_H_ */
diff -r 6fa783097ca1 -r 6112bcc5d1cf librazor/razor.h
--- a/librazor/razor.h	Sat Feb 11 09:49:58 2012 +0000
+++ b/librazor/razor.h	Sat Feb 11 23:50:26 2012 +0000
@@ -96,6 +96,18 @@
 };
 
 /**
+ * SECTION:error
+ * @title: Error reporting
+ * @short_description: A system for reporting errors.
+ *
+ * This object represents an error condition.
+ */
+struct razor_error;
+
+const char *razor_error_get_msg(struct razor_error *error);
+void razor_error_free(struct razor_error *error);
+
+/**
  * SECTION:atomic
  * @title: Atomic transactions
  * @short_description: File-based transactions that shouldn't half-succeed