Bugs fixed in vhdutils and vdiutils

- avoid infinite loop when searching for parent VDI
- VHD block bitmap is now flushed only when a "real" block is written to
- a virtual block in a Differencing VHD is now kept as such only if parent's block itself is virtual

FATtools/vdiutils.py

@@ -210,6 +210,7 @@ def __init__ (self, name, mode='rb'):
         if self.header.dwImageType == 4: # Differencing VDI
             parent=''
             for vdi in glob.glob('./*.vdi'):
+                if vdi.lower() == name.lower(): continue
                 parent=vdi
                 o=Image(vdi, "rb")
                 if o.header.sUuidCreate == self.header.sUuidLinkage:

FATtools/version.py

@@ -1 +1 @@
-__version__ = '1.0.29'
+__version__ = '1.0.30'

FATtools/vhdutils.py

@@ -586,8 +586,8 @@ def write1(self, s):
                 put=size
                 size=0
             if block == 0xFFFFFFFF:
-                # we keep a block virtualized until we write zeros
-                if s[i:i+put] == self.zero[:put]:
+                # we can keep a block virtualized until PARENT'S IS VIRTUALIZED AND we write zeros
+                if self.Parent.bat[self._pos//self.block] == 0xFFFFFFFF and s[i:i+put] == self.zero[:put]:
                     i+=put
                     self._pos+=put
                     if DEBUG&16: log("block #%d @0x%X is zeroed, virtualizing write", self._pos//self.block, (block*self.block)+self.header.u64TableOffset)
@@ -632,9 +632,10 @@ def copysect(vpos, sec):
             self.stream.write(s[i:i+put])
             i+=put
             self._pos+=put
-        if DEBUG&16: log("%s: flushing bitmap for block #%d at end", self.name, bmp.i)
-        self.stream.seek(bmp.i*512)
-        self.stream.write(bmp.bmp)
+        if bmp: # None if virtual writes only!
+            if DEBUG&16: log("%s: flushing bitmap for block #%d at end", self.name, bmp.i)
+            self.stream.seek(bmp.i*512)
+            self.stream.write(bmp.bmp)