Preserve first-position of some essential mill options (#42)

Fixes issue com-lihaoyi/mill#2123

Pull request: #42

millw

@@ -169,11 +169,20 @@ if [ -z "$MILL_MAIN_CLI" ] ; then
   MILL_MAIN_CLI="${0}"
 fi
 
+MILL_FIRST_ARG=""
+if [ "$1" = "--bsp" ] || [ "$1" = "-i" ] || [ "$1" = "--interactive" ] || [ "$1" = "--no-server" ] || [ "$1" = "--repl" ] || [ "$1" = "--help" ] ; then
+  # Need to preserve the first position of those listed options
+  MILL_FIRST_ARG=$1
+  shift
+fi
+
 unset MILL_DOWNLOAD_PATH
 unset MILL_OLD_DOWNLOAD_PATH
 unset OLD_MILL
 unset MILL_VERSION
 unset MILL_VERSION_TAG
 unset MILL_REPO_URL
 
-exec "${MILL}" -D "mill.main.cli=${MILL_MAIN_CLI}" "$@"
+# We don't quote MILL_FIRST_ARG on purpose, so we can expand the empty value without quotes
+# shellcheck disable=SC2086
+exec "${MILL}" $MILL_FIRST_ARG -D "mill.main.cli=${MILL_MAIN_CLI}" "$@"

millw.bat

@@ -23,18 +23,24 @@ set "MILL_REPO_URL=https://github.com/com-lihaoyi/mill"
 
 rem %~1% removes surrounding quotes
 if [%~1%]==[--mill-version] (
+  if not [%~2%]==[] (
+    set MILL_VERSION=%~2%
     rem shift command doesn't work within parentheses
-    if not [%~2%]==[] (
-        set MILL_VERSION=%~2%
-        set "STRIP_VERSION_PARAMS=true"
-    ) else (
-        echo You specified --mill-version without a version. 1>&2
-        echo Please provide a version that matches one provided on 1>&2
-        echo %MILL_REPO_URL%/releases 1>&2
-        exit /b 1
-    )
+    set "STRIP_VERSION_PARAMS=true"
+  ) else (
+    echo You specified --mill-version without a version. 1>&2
+    echo Please provide a version that matches one provided on 1>&2
+    echo %MILL_REPO_URL%/releases 1>&2
+    exit /b 1
+  )
 )
 
+if not defined STRIP_VERSION_PARAMS GOTO AfterStripVersionParams
+rem strip the: --mill-version {version}
+shift
+shift
+:AfterStripVersionParams
+
 if [!MILL_VERSION!]==[] (
   if exist .mill-version (
       set /p MILL_VERSION=<.mill-version
@@ -108,19 +114,57 @@ set MILL_DOWNLOAD_PATH=
 set MILL_VERSION=
 set MILL_REPO_URL=
 
-set MILL_PARAMS=%*
-
 if [!MILL_MAIN_CLI!]==[] (
     set "MILL_MAIN_CLI=%0"
 )
 
-if defined STRIP_VERSION_PARAMS (
+rem Need to preserve the first position of those listed options
+set MILL_FIRST_ARG=
+if [%~1%]==[--bsp] (
+  set MILL_FIRST_ARG=%1%
+) else (
+  if [%~1%]==[-i] (
+    set MILL_FIRST_ARG=%1%
+  ) else (
+    if [%~1%]==[--interactive] (
+      set MILL_FIRST_ARG=%1%
+    ) else (
+      if [%~1%]==[--no-server] (
+        set MILL_FIRST_ARG=%1%
+      ) else (
+        if [%~1%]==[--repl] (
+          set MILL_FIRST_ARG=%1%
+        ) else (
+          if [%~1%]==[--help] (
+            set MILL_FIRST_ARG=%1%
+          )
+        )
+      )
+    )
+  )
+)
+
+set "MILL_PARAMS=%*%"
+
+if not [!MILL_FIRST_ARG!]==[] (
+  if defined STRIP_VERSION_PARAMS (
+    for /f "tokens=1-3*" %%a in ("%*") do (
+        set "MILL_PARAMS=%%d"
+    )
+  ) else (
+    for /f "tokens=1*" %%a in ("%*") do (
+      set "MILL_PARAMS=%%b"
+    )
+  )
+) else (
+  if defined STRIP_VERSION_PARAMS (
     for /f "tokens=1-2*" %%a in ("%*") do (
         rem strip %%a - It's the "--mill-version" option.
         rem strip %%b - it's the version number that comes after the option.
         rem keep  %%c - It's the remaining options.
-        set MILL_PARAMS=%%c
+        set "MILL_PARAMS=%%c"
     )
+  )
 )
 
-"%MILL%" -D "mill.main.cli=%MILL_MAIN_CLI%" %MILL_PARAMS%
+"%MILL%" %MILL_FIRST_ARG% -D "mill.main.cli=%MILL_MAIN_CLI%" %MILL_PARAMS%