From ae7d142ac04cf51ba134750f3338f43af285a433 Mon Sep 17 00:00:00 2001
From: Eric Biggers <ebiggers3@gmail.com>
Date: Sun, 18 Oct 2015 19:39:35 -0500
Subject: [PATCH] wimlib_export_image(): improve duplicate image detection

---
 include/wimlib.h   |  8 ++++++--
 src/error.c        |  2 ++
 src/export_image.c | 23 +++++++++++++++++------
 3 files changed, 25 insertions(+), 8 deletions(-)

diff --git a/include/wimlib.h b/include/wimlib.h
index cdc29889..6842e35d 100644
--- a/include/wimlib.h
+++ b/include/wimlib.h
@@ -2493,11 +2493,12 @@ enum wimlib_error_code {
 	WIMLIB_ERR_MOUNTED_IMAGE_IS_BUSY              = 79,
 	WIMLIB_ERR_NOT_A_MOUNTPOINT                   = 80,
 	WIMLIB_ERR_NOT_PERMITTED_TO_UNMOUNT           = 81,
-	WIMLIB_ERR_FVE_LOCKED_VOLUME		      = 82,
+	WIMLIB_ERR_FVE_LOCKED_VOLUME                  = 82,
 	WIMLIB_ERR_UNABLE_TO_READ_CAPTURE_CONFIG      = 83,
-	WIMLIB_ERR_WIM_IS_INCOMPLETE		      = 84,
+	WIMLIB_ERR_WIM_IS_INCOMPLETE                  = 84,
 	WIMLIB_ERR_COMPACTION_NOT_POSSIBLE            = 85,
 	WIMLIB_ERR_IMAGE_HAS_MULTIPLE_REFERENCES      = 86,
+	WIMLIB_ERR_DUPLICATE_EXPORTED_IMAGE           = 87,
 };
 
 
@@ -2757,6 +2758,9 @@ wimlib_delete_path(WIMStruct *wim, int image,
  *
  * @return 0 on success; a ::wimlib_error_code value on failure.
  *
+ * @retval ::WIMLIB_ERR_DUPLICATE_EXPORTED_IMAGE
+ *	One or more of the source images had already been exported into the
+ *	destination WIM.
  * @retval ::WIMLIB_ERR_IMAGE_NAME_COLLISION
  * 	One or more of the names being given to an exported image was already in
  * 	use in the destination WIM.
diff --git a/src/error.c b/src/error.c
index af212db0..ea434912 100644
--- a/src/error.c
+++ b/src/error.c
@@ -340,6 +340,8 @@ static const tchar * const error_strings[] = {
 	[WIMLIB_ERR_IMAGE_HAS_MULTIPLE_REFERENCES]
 		= T("The WIM image cannot be modified because it is currently "
 		    "referenced from multiple places"),
+	[WIMLIB_ERR_DUPLICATE_EXPORTED_IMAGE]
+		= T("The destination WIM already contains one of the source images"),
 };
 
 WIMLIBAPI const tchar *
diff --git a/src/export_image.c b/src/export_image.c
index ff20a73f..da638322 100644
--- a/src/export_image.c
+++ b/src/export_image.c
@@ -3,7 +3,7 @@
  */
 
 /*
- * Copyright (C) 2012, 2013, 2014 Eric Biggers
+ * Copyright (C) 2012, 2013, 2014, 2015 Eric Biggers
  *
  * This file 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
@@ -128,7 +128,7 @@ wimlib_export_image(WIMStruct *src_wim,
 			     WIMLIB_EXPORT_FLAG_WIMBOOT))
 		return WIMLIB_ERR_INVALID_PARAM;
 
-	if (!src_wim || !dest_wim || src_wim == dest_wim)
+	if (!src_wim || !dest_wim)
 		return WIMLIB_ERR_INVALID_PARAM;
 
 	if (!wim_has_metadata(src_wim) || !wim_has_metadata(dest_wim))
@@ -153,6 +153,21 @@ wimlib_export_image(WIMStruct *src_wim,
 	}
 	orig_dest_image_count = dest_wim->hdr.image_count;
 
+	/* We don't yet support having a single WIMStruct contain duplicate
+	 * 'image_metadata' structures, so we must forbid this from happening.
+	 * A duplication is possible if 'src_wim == dest_wim', if the same image
+	 * is exported to the same destination WIMStruct multiple times, or if
+	 * an image is exported in an A => B => A manner.  */
+	for (src_image = start_src_image;
+	     src_image <= end_src_image; src_image++)
+	{
+		const struct wim_image_metadata *src_imd =
+				src_wim->image_metadata[src_image - 1];
+		for (int i = 0; i < dest_wim->hdr.image_count; i++)
+			if (dest_wim->image_metadata[i] == src_imd)
+				return WIMLIB_ERR_DUPLICATE_EXPORTED_IMAGE;
+	}
+
 	/* Blob checksums must be known before proceeding.  */
 	ret = wim_checksum_unhashed_blobs(src_wim);
 	if (ret)
@@ -249,10 +264,6 @@ wimlib_export_image(WIMStruct *src_wim,
 			dest_wim->hdr.boot_idx = dst_image;
 	}
 
-	if (export_flags & WIMLIB_EXPORT_FLAG_GIFT) {
-		free_blob_table(src_wim->blob_table);
-		src_wim->blob_table = NULL;
-	}
 	return 0;
 
 out_rollback:
-- 
2.43.0