2011-11-23: write .statichgrepo, print.css and screen.css only if they were

write .statichgrepo, print.css and screen.css only if they were changed.

diff --git a/site.py b/site.py
--- a/site.py
+++ b/site.py
@@ -258,6 +258,20 @@ def writesourcetree(ui, repo, target, na
             f.write(createindex(target, ctx))
             f.write(templates["foot"].replace("{reponame}", "<a href='../../'>"+name+"</a>"))
 
+def samefilecontent(filepath1, filepath2): 
+    """Check if the content of the two referenced files is equal."""
+    try: 
+        with open(filepath1) as f1: 
+            with open(filepath2) as f2: 
+                return f1.read() == f2.read()
+    except OSError: return False
+
+def contentequals(filepath, content): 
+    """Check if the files content is content."""
+    try: 
+        with open(filepath) as f: 
+            return f.read() == content
+    except OSError: return not content
 
 def parsesite(ui, repo, target, **opts):
     """Create the static folder."""
@@ -279,16 +293,18 @@ def parsesite(ui, repo, target, **opts):
 
     # first the stylesheets
     screenstyle = opts["screenstyle"]
-    if screenstyle:
-        shutil.copyfile(screenstyle, join(target, "style.css"))
-    else:
+    screenfile = join(target, "style.css")
+    if screenstyle and not samefilecontent(screenstyle, screenfile):
+        shutil.copyfile(screenstyle, screenfile)
+    elif not contentequals(screenfile,templates["screenstyle"]):
         with open(join(target, "style.css"), "w") as f:
             f.write(templates["screenstyle"])
     printstyle = opts["printstyle"]
-    if printstyle:
-        shutil.copyfile(printstyle, join(target, "print.css"))
-    else:
-        with open(join(target, "print.css"), "w") as f:
+    printfile = join(target, "print.css")
+    if printstyle and not samefilecontent(printstyle, printfile):
+        shutil.copyfile(printstyle, printfile)
+    elif not contentequals(printfile, templates["printstyle"]):
+        with open(printfile, "w") as f:
             f.write(templates["printstyle"])
 
     # then the overview