Bug 806814. r=rstrong

--HG--
extra : transplant_source : %92wf%5D%FF%F3%3E%A2%C3l%FF%01%9B%BBY%E3%165%DD%10

mail/installer/windows/nsis/installer.nsi

@@ -945,6 +945,10 @@ FunctionEnd
 # Initialization Functions
 
 Function .onInit
+  ; Remove the current exe directory from the search order.
+  ; This only effects LoadLibrary calls and not implicitly loaded DLLs.
+  System::Call 'kernel32::SetDllDirectoryW(w "")'
+
   StrCpy $PageName ""
   StrCpy $LANGUAGE 0
   ${SetBrandNameVars} "$EXEDIR\core\distribution\setup.ini"

mail/installer/windows/nsis/maintenanceservice_installer.nsi

@@ -106,6 +106,10 @@ ShowUnInstDetails nevershow
 BrandingText " "
 
 Function .onInit
+  ; Remove the current exe directory from the search order.
+  ; This only effects LoadLibrary calls and not implicitly loaded DLLs.
+  System::Call 'kernel32::SetDllDirectoryW(w "")'
+
   SetSilent silent
 !ifdef HAVE_64BIT_OS
   ; We plan to eventually enable 64bit native builds to use the maintenance
@@ -123,6 +127,10 @@ Function .onInit
 FunctionEnd
 
 Function un.onInit
+  ; Remove the current exe directory from the search order.
+  ; This only effects LoadLibrary calls and not implicitly loaded DLLs.
+  System::Call 'kernel32::SetDllDirectoryW(w "")'
+
   StrCpy $BrandFullNameDA "${MaintFullName}"
   StrCpy $BrandFullName "${MaintFullName}"
 FunctionEnd

mail/installer/windows/nsis/uninstaller.nsi

@@ -510,6 +510,10 @@ FunctionEnd
 # Initialization Functions
 
 Function .onInit
+  ; Remove the current exe directory from the search order.
+  ; This only effects LoadLibrary calls and not implicitly loaded DLLs.
+  System::Call 'kernel32::SetDllDirectoryW(w "")'
+
   ; We need this set up for most of the helper.exe operations.
   !ifdef AppName
   ${InitHashAppModelId} "$INSTDIR" "Software\Mozilla\${AppName}\TaskBarIDs"
@@ -518,6 +522,10 @@ Function .onInit
 FunctionEnd
 
 Function un.onInit
+  ; Remove the current exe directory from the search order.
+  ; This only effects LoadLibrary calls and not implicitly loaded DLLs.
+  System::Call 'kernel32::SetDllDirectoryW(w "")'
+
   StrCpy $LANGUAGE 0
 
   ${un.UninstallUnOnInitCommon}