Handled batch parameters better

and fixed error in appveyor config file

appveyor.yml

@@ -90,7 +90,7 @@ install:
 
 before_build:
 # Generate VS2019 solution
-- cmd: '%SCRIPTS%\generate_solution_vs2019.bat %CONFIG_PARTIAL% -s'
+- cmd: '%SCRIPTS%\generate_solution_vs2019.bat -s'
 
 
 #---------------------------------#
@@ -112,7 +112,7 @@ after_build:
 # show content of test dir to see if report is created.
 - cmd: 'dir bin\%CONFIG_PARTIAL%-%OS_PARTIAL%-%PLAT_PARTIAL%\tests'
 # Create installer [it works because appveyor image comes with NSIS installed]
-- cmd: '%SCRIPTS%\create_installer.bat -s'
+- cmd: '%SCRIPTS%\create_installer.bat %CONFIG_PARTIAL% -s'
 # Renaming installer to include version in its name
 - cmd: 'ren %OUTPUT_FOLDER%\installers\%PRODUCT_NAME%Setup.exe "%PRODUCT_NAME%-%FILE_VERSION%-setup.exe"'
 

scripts/create_installer.bat

@@ -5,18 +5,26 @@
 @rem Prevent env variables to escape to the calling environment
 SETLOCAL
 
+@rem redefine variables in case already defined in the calling environment
 SET CONFIG=%~1
 SET DEFAULT_CONFIG=Release
+SET SILENT_MODE=false
 
 IF "%CONFIG%" == "" (
     SET CONFIG=%DEFAULT_CONFIG%
     echo No Configuration passed. Defaulted to %CONFIG%
     echo Usage: create_installer.bat ^<configuration^> [-s]
+) ELSE IF "%CONFIG%" == "-s" (
+    SET SILENT_MODE=true
+    SET CONFIG=%DEFAULT_CONFIG%
+    echo No Configuration passed. Defaulted to %CONFIG%
+    echo Usage: create_installer.bat ^<configuration^> [-s]
+) ELSE IF "%CONFIG:~0,1%" == "-" (
+    SET CONFIG=%DEFAULT_CONFIG%
+    echo No Configuration passed. Defaulted to %CONFIG%
+    echo Usage: create_installer.bat ^<configuration^> [-s]
 )
 
-@rem redefine variables in case already defined in the calling environment
-SET SILENT_MODE=false
-
 SHIFT
 :args
 SET PARAM=%~1