From 287ab91739e5780834066f497db9b78755436912 Mon Sep 17 00:00:00 2001
From: Jeffrey Pfau <jeffrey@endrift.com>
Date: Fri, 21 Oct 2016 23:18:18 -0700
Subject: [PATCH] VFS: Allow truncating memory chunk VFiles

---
 CHANGES                |  1 +
 src/util/vfs/vfs-mem.c | 12 ++++++------
 2 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/CHANGES b/CHANGES
index 500d8736b..b23323b82 100644
--- a/CHANGES
+++ b/CHANGES
@@ -26,6 +26,7 @@ Misc:
  - GBA Video, GB Video: Colors are now fully scaled
  - PSP2: Improved controller rumble
  - GB, GBA: Prevent loading null ROMs
+ - VFS: Allow truncating memory chunk VFiles
 
 0.5.1: (2016-10-05)
 Bugfixes:
diff --git a/src/util/vfs/vfs-mem.c b/src/util/vfs/vfs-mem.c
index d9a1a2520..174ef6587 100644
--- a/src/util/vfs/vfs-mem.c
+++ b/src/util/vfs/vfs-mem.c
@@ -116,7 +116,11 @@ void _vfmExpand(struct VFileMem* vfm, size_t newSize) {
 	void* oldBuf = vfm->mem;
 	vfm->mem = anonymousMemoryMap(newSize);
 	if (oldBuf) {
-		memcpy(vfm->mem, oldBuf, vfm->size);
+		if (newSize < vfm->size) {
+			memcpy(vfm->mem, oldBuf, newSize);
+		} else {
+			memcpy(vfm->mem, oldBuf, vfm->size);
+		}
 		mappedMemoryFree(oldBuf, vfm->size);
 	}
 	vfm->size = newSize;
@@ -270,11 +274,7 @@ void _vfmUnmap(struct VFile* vf, void* memory, size_t size) {
 
 void _vfmTruncate(struct VFile* vf, size_t size) {
 	struct VFileMem* vfm = (struct VFileMem*) vf;
-	if (size > vfm->size) {
-		_vfmExpand(vfm, size);
-	} else {
-		// TODO
-	}
+	_vfmExpand(vfm, size);
 }
 
 void _vfmTruncateNoop(struct VFile* vf, size_t size) {