From: Eric Biggers <ebiggers3@gmail.com>
Date: Sun, 15 Jan 2017 01:00:13 +0000 (-0800)
Subject: Don't generate GUID in wimlib_create_new_wim()
X-Git-Tag: v1.11.0~5
X-Git-Url: https://wimlib.net/git/?p=wimlib;a=commitdiff_plain;h=831eeaad4513475ce947efaef16fc79ab3997444

Don't generate GUID in wimlib_create_new_wim()

It's not necessary to generate a GUID in wimlib_create_new_wim() because
one is generated later by wimlib_write(), and nothing seems to assume
that a WIMStruct not yet backed by a file has a valid GUID.  This saves
a call to get_random_bytes().  Also remove some unnecessary
initializations to 0.
---

diff --git a/src/wim.c b/src/wim.c
index 937b834b..ec345a93 100644
--- a/src/wim.c
+++ b/src/wim.c
@@ -172,31 +172,25 @@ wimlib_create_new_wim(enum wimlib_compression_type ctype, WIMStruct **wim_ret)
 	if (!wim)
 		return WIMLIB_ERR_NOMEM;
 
-	wim->xml_info = xml_new_info_struct();
-	wim->blob_table = new_blob_table(64);
-	if (!wim->xml_info || !wim->blob_table) {
-		wimlib_free(wim);
-		return WIMLIB_ERR_NOMEM;
-	}
-
-	/* Fill in wim->hdr with default values  */
+	/* Fill in wim->hdr with default values */
 	wim->hdr.magic = WIM_MAGIC;
 	wim->hdr.wim_version = WIM_VERSION_DEFAULT;
-	wim->hdr.flags = 0;
-	wim->hdr.chunk_size = 0;
-	generate_guid(wim->hdr.guid);
 	wim->hdr.part_number = 1;
 	wim->hdr.total_parts = 1;
-	wim->hdr.image_count = 0;
-	wim->hdr.boot_idx = 0;
-
 	wim->compression_type = WIMLIB_COMPRESSION_TYPE_NONE;
-	wim->chunk_size = wim->hdr.chunk_size;
 
-	/* Set the output compression type  */
+	/* Set the output compression type */
 	wim->out_compression_type = ctype;
 	wim->out_chunk_size = wim_default_nonsolid_chunk_size(ctype);
 
+	/* Allocate an empty XML info and blob table */
+	wim->xml_info = xml_new_info_struct();
+	wim->blob_table = new_blob_table(64);
+	if (!wim->xml_info || !wim->blob_table) {
+		wimlib_free(wim);
+		return WIMLIB_ERR_NOMEM;
+	}
+
 	*wim_ret = wim;
 	return 0;
 }