buildDotnetModule: parse version before passing it to dotnet

This avoids problems when the Nix version attribute does not fit the
format required by .NET

pkgs/build-support/dotnet/build-dotnet-module/default.nix

@@ -158,6 +158,22 @@ stdenvNoCC.mkDerivation (args // {
     dotnet-sdk
   ];
 
+  # Parse the version attr into a format acceptable for the Version msbuild property
+  # The actual version attr is saved in InformationalVersion, which accepts an arbitrary string
+  versionForDotnet = if !(lib.hasAttr "version" args) || args.version == null
+  then null else let
+    components = lib.pipe args.version [
+      lib.splitVersion
+      (lib.filter (x: (lib.strings.match "[0-9]+" x) != null))
+      (lib.filter (x: (lib.toInt x) < 65535)) # one version component in dotnet has to fit in 16 bits
+    ];
+  in if (lib.length components) == 0
+  then null
+  else lib.concatStringsSep "." ((lib.take 4 components)
+    ++ (if (lib.length components) < 4
+       then lib.replicate (4 - (lib.length components)) "0"
+       else [ ]));
+
   makeWrapperArgs = args.makeWrapperArgs or [ ] ++ [
     "--prefix LD_LIBRARY_PATH : ${dotnet-sdk.icu}/lib"
   ];

pkgs/build-support/dotnet/build-dotnet-module/hooks/dotnet-build-hook.sh

@@ -24,8 +24,13 @@ dotnetBuildHook() {
         dotnetBuildFlags+=("-p:UseAppHost=true")
     fi
 
+    local versionFlags=()
     if [ "${version-}" ]; then
-        local -r versionFlag="-p:Version=${version-}"
+        versionFlags+=("-p:InformationalVersion=${version-}")
+    fi
+
+    if [ "${versionForDotnet-}" ]; then
+        versionFlags+=("-p:Version=${versionForDotnet-}")
     fi
 
     dotnetBuild() {
@@ -43,7 +48,7 @@ dotnetBuildHook() {
             -p:Deterministic=true \
             --configuration "@buildType@" \
             --no-restore \
-            ${versionFlag-} \
+            ${versionFlags[@]} \
             ${runtimeIdFlags[@]} \
             ${dotnetBuildFlags[@]}  \
             ${dotnetFlags[@]}