Standardise os.sha256_file to be lowercase across platforms

Author: qaisjp

utils/buildactions/install_cef.lua

@@ -9,7 +9,7 @@ local CEF_URL_SUFFIX = "_windows32_minimal.tar.bz2"
 
 -- Change here to update CEF version
 local CEF_VERSION = "80.0.4+g74f7b0c+chromium-80.0.3987.122"
-local CEF_HASH = "8FD8E24AF196F00FEAAA1553496BAE99D8196BA023D0DD0FE44EFEEE93B04DFC"
+local CEF_HASH = "8fd8e24af196f00feaaa1553496bae99d8196ba023d0dd0fe44efeee93b04dfc"
 
 function make_cef_download_url()
 	return CEF_URL_PREFIX..http.escapeUrlParam(CEF_VERSION)..CEF_URL_SUFFIX

utils/buildactions/install_discord.lua

@@ -9,7 +9,7 @@ local DISCORD_VENDOR = "vendor/discordgsdk"
 
 -- Change these to update the version
 local DISCORD_TAG = "v2020-11-02_21-48-56"
-local DISCORD_HASH = "4CCEEED0D8B41BDC67C44A6DDCCCF42288AF933E1F7284C591327178C391AA39"
+local DISCORD_HASH = "4cceeed0d8b41bdc67c44a6ddcccf42288af933e1f7284c591327178c391aa39"
 
 newaction {
 	trigger = "install_discord",

utils/buildactions/utils.lua

@@ -84,12 +84,17 @@ function os.expanddir_wildcard(from, to)
 end
 
 function os.sha256_file(path)
+	local s, errc
 	if os.host() == "windows" then
-		local s, errc = os.outputof(string.format("powershell -Command (Get-FileHash \"%s\" -Algorithm SHA256).Hash", path))
-		return (errc == 0) and s or ""
+		s, errc = os.outputof(string.format("powershell -Command (Get-FileHash \"%s\" -Algorithm SHA256).Hash", path))
 	else
-		return os.outputof(string.format("sha256sum \"%s\" | awk '{ print $1 }'", path))
+		s, errc = os.outputof(string.format("sha256sum \"%s\" | awk '{ print $1 }'", path))
 	end
+	if errc ~= 0 then
+		print("Error os.sha256_file: ", errc)
+		return ""
+	end
+	return s:lower()
 end
 
 function os.extract_archive(archive_path, target_path, override)