Avoid overwriting dicts.dat if it is unchanged

com/win32com/client/gencache.py

@@ -546,27 +546,25 @@ def AddModuleToCache(typelibclsid, lcid, major, minor, verbose = 1, bFlushNow =
  # if mod._in_gencache_ is already true, then we are reloading this
  # module - this doesn't mean anything special though!
  mod._in_gencache_ = 1
- dict = mod.CLSIDToClassMap
  info = str(typelibclsid), lcid, major, minor
- for clsid, cls in dict.items():
- clsidToTypelib[clsid] = info
+ dict_modified = False
 
- dict = mod.CLSIDToPackageMap
- for clsid, name in dict.items():
- clsidToTypelib[clsid] = info
+ def SetTypelibForAllClsids(dict):
+ nonlocal dict_modified
+ for clsid, cls in dict.items():
+ if clsidToTypelib.get(clsid) != info:
+ clsidToTypelib[clsid] = info
+ dict_modified = True
 
- dict = mod.VTablesToClassMap
- for clsid, cls in dict.items():
- clsidToTypelib[clsid] = info
-
- dict = mod.VTablesToPackageMap
- for clsid, cls in dict.items():
- clsidToTypelib[clsid] = info
+ SetTypelibForAllClsids(mod.CLSIDToClassMap)
+ SetTypelibForAllClsids(mod.CLSIDToPackageMap)
+ SetTypelibForAllClsids(mod.VTablesToClassMap)
+ SetTypelibForAllClsids(mod.VTablesToPackageMap)
 
  # If this lib was previously redirected, drop it
  if info in versionRedirectMap:
  del versionRedirectMap[info]
- if bFlushNow:
+ if bFlushNow and dict_modified:
  _SaveDicts()
 
 def GetGeneratedInfos():