Coverity: [skip ci] Bad use of null-like value

src/Mod/PartDesign/FeatureHole/HoleGui.py

@@ -57,6 +57,7 @@ class HoleGui:
             return
         if selection[0].DocumentName != doc.Name:
             QtGui.QMessageBox.critical(mw, "Wrong document", "Please select a face in the active document")
+            return
         # Note: For some reason setting the Support property here breaks all sorts of things.
         #       It is done in TaskHole.updateUI() instead
 
@@ -64,6 +65,7 @@ class HoleGui:
         body = FreeCADGui.activeView().getActiveObject("pdbody");
         if body is None:
             QtGui.QMessageBox.critical(mw, "No active body", "Please create a body or make a body active")
+            return
     
         feature = doc.addObject("Part::FeaturePython","Hole")
         hole = Hole(feature)

src/Mod/PartDesign/fcsprocket/fcsprocket.py

@@ -29,9 +29,9 @@ def makeSprocket(P, N, Dr):
     w = FCWireBuilder()
     sprocket.CreateSprocket(w, P, N, Dr)
     sprocketw = Part.Wire([o.toShape() for o in w.wire])
-    sprocket = doc.addObject("Part::Feature", "Sprocket")
-    sprocket.Shape = sprocketw
-    return sprocket
+    sprocketf = doc.addObject("Part::Feature", "Sprocket")
+    sprocketf.Shape = sprocketw
+    return sprocketf
 
 class FCWireBuilder(object):
     """A helper class to prepare a Part.Wire object"""

src/Mod/Ship/TankInstance.py

@@ -173,6 +173,7 @@ class Tank:
             return Vector()
         if vol >= fp.Shape.Volume:
             vol = 0.0
+            cog = Vector()
             for solid in fp.Shape.Solids:
                 vol += solid.Volume
                 sCoG = solid.CenterOfMass

src/Mod/Start/StartPage/StartPage.py

@@ -320,11 +320,11 @@ def handle():
                     f = QtCore.QFile(path)
                     if f.open(QtCore.QIODevice.ReadOnly | QtCore.QFile.Text):
                         ALTCSS = encode(QtCore.QTextStream(f).readAll())
+                        HTML = HTML.replace("<!--QSS-->","<style type=\"text/css\">"+ALTCSS+"</style>")
                 else:
                     with open(path, 'r') as f:
                         ALTCSS = encode(f.read())
-
-                HTML = HTML.replace("<!--QSS-->","<style type=\"text/css\">"+ALTCSS+"</style>")
+                        HTML = HTML.replace("<!--QSS-->","<style type=\"text/css\">"+ALTCSS+"</style>")
 
     # turn tips off if needed
 

src/Tools/offlinedoc/buildwikiindex.py

@@ -152,7 +152,7 @@ def getlinks(html):
             rg = re.findall('href="\/wiki\/(.*?)"',l)
             if "images" in rg:
                 rg = None
-            if "mediawiki" in rg:
+            elif "mediawiki" in rg:
                 rg = None
         if rg:
             rg = rg[0]