windows-msi: introduce a Powershell script for bumping version.m4

This is required for providing Windows snapshot packages

Signed-off-by: Samuli Seppänen <samuli@openvpn.net>

Author: mattock

windows-msi/bump-version.m4.ps1

@@ -0,0 +1,58 @@
+# Change PRODUCT_CODE and PRODUCT_VERSION in version.m4. Primarily intended to
+# be used within a CI system, not for release builds.
+
+<#
+.Description
+Get the current value of PRODUCT_VERSION in version.m4. This is needed so that we can increment it. Example: 2.5.028.
+#>
+Function Get-ProductVersion {
+    ForEach ($line in (Get-Content version.m4)) {
+        if ($line -match '^define\(\[PRODUCT_VERSION\], \[(.*?)\]\)') {
+            $ProductVersion = $Matches[1]
+	    break
+	}
+    }
+
+    $ProductVersion
+}
+
+<#
+.Description
+Increment the last digit in PRODUCTION_VERSION. Only used internally.
+#>
+Function Increment-Counter {
+    param (
+        [string]$Counter
+    )
+
+    # String off leading zeroes, if any
+    $Counter = $Counter -replace '^0+', ''
+    $IntCounter = [int]$Counter
+    $IntCounter += 1
+    $Counter = [string]$IntCounter
+
+    # Add back leading zeroes, if any
+    $Counter = $Counter.PadLeft(3, '0')
+    $Counter
+}
+
+<#
+.Description
+Create an incremented PRODUCT_VERSION (e.g. 2.5.029).
+#>
+Function New-ProductVersion {
+    $OldProductVersion = (Get-ProductVersion) -match '(\d\.\d?)\.(\d\d\d?)'
+    $Version = $Matches[1]
+    $Counter = $Matches[2]
+    $Counter = Increment-Counter -Counter $Counter
+    "${Version}.${Counter}"
+}
+
+# Get updated values for PRODUCT_VERSION and PRODUCT_CODE
+$NewProductVersion = New-ProductVersion
+$NewProductCode = (New-Guid).ToString().ToUpper()
+
+# Replace old values with the newly generated ones, overwriting version.m4
+$version_m4 = (Get-Content version.m4)
+$version_m4 -replace '^define\(\[PRODUCT_CODE\], \[\{(?<ProductCode>.*)\}]\)', "define([PRODUCT_CODE], [{${NewProductCode}}])" `
+            -replace '^define\(\[PRODUCT_VERSION\], \[(.*?)\]\)', "define([PRODUCT_VERSION], [${NewProductVersion}])" | Out-File -Encoding ASCII version.m4