From: Patrick Lam <plam@MIT.EDU>
Date: Wed, 16 Nov 2005 17:49:01 +0000 (+0000)
Subject: src/fccache.c (FcDirCacheProduce)
X-Git-Tag: fc-2_3_93~45
X-Git-Url: https://git.wh0rd.org/?a=commitdiff_plain;h=8e351527bb87798e9b796e12a3b1ee6229536a28;p=fontconfig.git

src/fccache.c (FcDirCacheProduce)
Fix case where alignment bytes bumped up metadata->count causing
    unwarranted failures to write cache files. (Reported by Stephan Kulow).
---

diff --git a/ChangeLog b/ChangeLog
index f2b0ec2..f803d66 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2005-11-16  Patrick Lam  <plam@mit.edu>
+	* src/fccache.c (FcDirCacheProduce)
+	
+	Fix case where alignment bytes bumped up metadata->count
+	causing unwarranted failures to write cache files.  
+	(Reported by Stephan Kulow).
+
 2005-11-16  Patrick Lam  <plam@mit.edu>
 	* src/fccache.c (FcDirCacheProduce):
 	* src/fccharset.c (FcCharSetDistributeBytes):
diff --git a/src/fccache.c b/src/fccache.c
index af8a318..84a366e 100644
--- a/src/fccache.c
+++ b/src/fccache.c
@@ -793,7 +793,7 @@ FcDirCacheProduce (FcFontSet *set, FcCache *metadata)
 {
     void * current_dir_block, * final_dir_block;
     static unsigned int rand_state = 0;
-    int bank;
+    int bank, needed_bytes_no_align;
 
     if (!rand_state) 
 	rand_state = time(0L);
@@ -804,20 +804,27 @@ FcDirCacheProduce (FcFontSet *set, FcCache *metadata)
 
     memset (metadata, 0, sizeof(FcCache));
     FcFontSetNewBank();
-    metadata->count = FcFontSetNeededBytes (set) + 
+    needed_bytes_no_align = FcFontSetNeededBytes (set);
+    metadata->count = needed_bytes_no_align + 
 	FcFontSetNeededBytesAlign ();
     metadata->magic = FC_CACHE_MAGIC;
     metadata->bank = bank;
 
-    if (!metadata->count) /* not a failure, no fonts to write */
+    if (!needed_bytes_no_align) /* not a failure, no fonts to write */
+    {
+	/* no, you don't really need to write any bytes at all. */
+	metadata->count = 0;
 	return 0;
+    }
 
     current_dir_block = malloc (metadata->count);
     if (!current_dir_block)
 	goto bail;
+    // shut up valgrind
+    memset (current_dir_block, 0, metadata->count);
     final_dir_block = FcFontSetDistributeBytes (metadata, current_dir_block);
 
-    if ((char *)current_dir_block + metadata->count != final_dir_block)
+    if ((void *)((char *)current_dir_block+metadata->count) < final_dir_block)
 	goto bail;
 			      
     if (!FcFontSetSerialize (bank, set))