Work around Windows bug microsoft/terminal#15212 (emscripten-core#19212)

* Work around Windows bug microsoft/terminal#15212 where %~dp0 expansion is broken, by attempting to look up emcc first in EMSCRIPTEN, and then in PATH if it cannot be expanded to via %~dp0. Add a new test other.test_windows_batch_file_dp0_expansion_bug to check for this scenario.

* Update bat scripts to avoid ':' inside if() blocks.

em++.bat

@@ -5,6 +5,9 @@
 :: To make modifications to this file, edit `tools/run_python_compiler.bat` and
 :: then run `tools/create_entry_points.py`
 
+:: N.b. In Windows .bat scripts, the ':' character cannot appear inside any if () blocks,
+:: or there will be a parsing error.
+
 :: All env. vars specified in this file are to be local only to this script.
 @setlocal
 :: -E will not ignore _PYTHON_SYSCONFIGDATA_NAME an internal
@@ -15,13 +18,34 @@
   set EM_PY=python
 )
 
+:: Work around Windows bug https://github.com/microsoft/terminal/issues/15212 : If this
+:: script is invoked via enclosing the invocation in quotes via PATH lookup, then %~f0 and
+:: %~dp0 expansions will not work.
+:: So first try if %~dp0 might work, and if not, manually look up this script from PATH.
+@if exist %~f0 (
+  set MYDIR=%~dp0
+  goto FOUND_MYDIR
+)
+@for %%I in (%~n0.bat) do (
+  @if exist %%~$PATH:I (
+    set MYDIR=%%~dp$PATH:I
+  ) else (
+    echo Fatal Error! Due to a Windows bug, we are unable to locate the path to %~n0.bat.
+    echo To help this issue, try removing unnecessary quotes in the invocation of emcc,
+    echo or add Emscripten directory to PATH.
+    echo See github.com/microsoft/terminal/issues/15212 and
+    echo github.com/emscripten-core/emscripten/issues/19207 for more details.
+  )
+)
+:FOUND_MYDIR
+
 :: If _EMCC_CCACHE is not set, do a regular invocation of the python compiler driver.
 :: Otherwise remove the ccache env. var, and then reinvoke this script with ccache enabled.
 @if "%_EMCC_CCACHE%"=="" (
-  set CMD="%EM_PY%" -E "%~dp0\%~n0.py"
+  set CMD="%EM_PY%" -E "%MYDIR%%~n0.py"
 ) else (
   set _EMCC_CCACHE=
-  set CMD=ccache "%~dp0\%~n0.bat"
+  set CMD=ccache "%MYDIR%%~n0.bat"
 )
 
 :: Python Windows bug https://bugs.python.org/issue34780: If this script was invoked via a

em-config.bat

@@ -5,6 +5,9 @@
 :: To make modifications to this file, edit `tools/run_python.bat` and then run
 :: `tools/create_entry_points.py`
 
+:: N.b. In Windows .bat scripts, the ':' character cannot appear inside any if () blocks,
+:: or there will be a parsing error.
+
 :: All env. vars specified in this file are to be local only to this script.
 @setlocal
 :: -E will not ignore _PYTHON_SYSCONFIGDATA_NAME an internal
@@ -15,6 +18,27 @@
   set EM_PY=python
 )
 
+:: Work around Windows bug https://github.com/microsoft/terminal/issues/15212 : If this
+:: script is invoked via enclosing the invocation in quotes via PATH lookup, then %~f0 and
+:: %~dp0 expansions will not work.
+:: So first try if %~dp0 might work, and if not, manually look up this script from PATH.
+@if exist %~f0 (
+  set MYDIR=%~dp0
+  goto FOUND_MYDIR
+)
+@for %%I in (%~n0.bat) do (
+  @if exist %%~$PATH:I (
+    set MYDIR=%%~dp$PATH:I
+  ) else (
+    echo Fatal Error! Due to a Windows bug, we are unable to locate the path to %~n0.bat.
+    echo To help this issue, try removing unnecessary quotes in the invocation of emcc,
+    echo or add Emscripten directory to PATH.
+    echo See github.com/microsoft/terminal/issues/15212 and
+    echo github.com/emscripten-core/emscripten/issues/19207 for more details.
+  )
+)
+:FOUND_MYDIR
+
 :: Python Windows bug https://bugs.python.org/issue34780: If this script was invoked via a
 :: shared stdin handle from the parent process, and that parent process stdin handle is in
 :: a certain state, running python.exe might hang here. To work around this, if
@@ -47,16 +71,16 @@
 )
 
 :NORMAL_EXIT
-@"%EM_PY%" -E "%~dp0\%~n0.py" %*
+@"%EM_PY%" -E "%MYDIR%%~n0.py" %*
 @exit %ERRORLEVEL%
 
 :MUTE_STDIN
-@"%EM_PY%" -E "%~dp0\%~n0.py" %* < NUL
+@"%EM_PY%" -E "%MYDIR%%~n0.py" %* < NUL
 @exit /b %ERRORLEVEL%
 
 :MUTE_STDIN_EXIT
-@"%EM_PY%" -E "%~dp0\%~n0.py" %* < NUL
+@"%EM_PY%" -E "%MYDIR%%~n0.py" %* < NUL
 @exit %ERRORLEVEL%
 
 :NORMAL
-@"%EM_PY%" -E "%~dp0\%~n0.py" %*
+@"%EM_PY%" -E "%MYDIR%%~n0.py" %*

emar.bat

@@ -5,6 +5,9 @@
 :: To make modifications to this file, edit `tools/run_python.bat` and then run
 :: `tools/create_entry_points.py`
 
+:: N.b. In Windows .bat scripts, the ':' character cannot appear inside any if () blocks,
+:: or there will be a parsing error.
+
 :: All env. vars specified in this file are to be local only to this script.
 @setlocal
 :: -E will not ignore _PYTHON_SYSCONFIGDATA_NAME an internal
@@ -15,6 +18,27 @@
   set EM_PY=python
 )
 
+:: Work around Windows bug https://github.com/microsoft/terminal/issues/15212 : If this
+:: script is invoked via enclosing the invocation in quotes via PATH lookup, then %~f0 and
+:: %~dp0 expansions will not work.
+:: So first try if %~dp0 might work, and if not, manually look up this script from PATH.
+@if exist %~f0 (
+  set MYDIR=%~dp0
+  goto FOUND_MYDIR
+)
+@for %%I in (%~n0.bat) do (
+  @if exist %%~$PATH:I (
+    set MYDIR=%%~dp$PATH:I
+  ) else (
+    echo Fatal Error! Due to a Windows bug, we are unable to locate the path to %~n0.bat.
+    echo To help this issue, try removing unnecessary quotes in the invocation of emcc,
+    echo or add Emscripten directory to PATH.
+    echo See github.com/microsoft/terminal/issues/15212 and
+    echo github.com/emscripten-core/emscripten/issues/19207 for more details.
+  )
+)
+:FOUND_MYDIR
+
 :: Python Windows bug https://bugs.python.org/issue34780: If this script was invoked via a
 :: shared stdin handle from the parent process, and that parent process stdin handle is in
 :: a certain state, running python.exe might hang here. To work around this, if
@@ -47,16 +71,16 @@
 )
 
 :NORMAL_EXIT
-@"%EM_PY%" -E "%~dp0\%~n0.py" %*
+@"%EM_PY%" -E "%MYDIR%%~n0.py" %*
 @exit %ERRORLEVEL%
 
 :MUTE_STDIN
-@"%EM_PY%" -E "%~dp0\%~n0.py" %* < NUL
+@"%EM_PY%" -E "%MYDIR%%~n0.py" %* < NUL
 @exit /b %ERRORLEVEL%
 
 :MUTE_STDIN_EXIT
-@"%EM_PY%" -E "%~dp0\%~n0.py" %* < NUL
+@"%EM_PY%" -E "%MYDIR%%~n0.py" %* < NUL
 @exit %ERRORLEVEL%
 
 :NORMAL
-@"%EM_PY%" -E "%~dp0\%~n0.py" %*
+@"%EM_PY%" -E "%MYDIR%%~n0.py" %*

embuilder.bat

@@ -5,6 +5,9 @@
 :: To make modifications to this file, edit `tools/run_python.bat` and then run
 :: `tools/create_entry_points.py`
 
+:: N.b. In Windows .bat scripts, the ':' character cannot appear inside any if () blocks,
+:: or there will be a parsing error.
+
 :: All env. vars specified in this file are to be local only to this script.
 @setlocal
 :: -E will not ignore _PYTHON_SYSCONFIGDATA_NAME an internal
@@ -15,6 +18,27 @@
   set EM_PY=python
 )
 
+:: Work around Windows bug https://github.com/microsoft/terminal/issues/15212 : If this
+:: script is invoked via enclosing the invocation in quotes via PATH lookup, then %~f0 and
+:: %~dp0 expansions will not work.
+:: So first try if %~dp0 might work, and if not, manually look up this script from PATH.
+@if exist %~f0 (
+  set MYDIR=%~dp0
+  goto FOUND_MYDIR
+)
+@for %%I in (%~n0.bat) do (
+  @if exist %%~$PATH:I (
+    set MYDIR=%%~dp$PATH:I
+  ) else (
+    echo Fatal Error! Due to a Windows bug, we are unable to locate the path to %~n0.bat.
+    echo To help this issue, try removing unnecessary quotes in the invocation of emcc,
+    echo or add Emscripten directory to PATH.
+    echo See github.com/microsoft/terminal/issues/15212 and
+    echo github.com/emscripten-core/emscripten/issues/19207 for more details.
+  )
+)
+:FOUND_MYDIR
+
 :: Python Windows bug https://bugs.python.org/issue34780: If this script was invoked via a
 :: shared stdin handle from the parent process, and that parent process stdin handle is in
 :: a certain state, running python.exe might hang here. To work around this, if
@@ -47,16 +71,16 @@
 )
 
 :NORMAL_EXIT
-@"%EM_PY%" -E "%~dp0\%~n0.py" %*
+@"%EM_PY%" -E "%MYDIR%%~n0.py" %*
 @exit %ERRORLEVEL%
 
 :MUTE_STDIN
-@"%EM_PY%" -E "%~dp0\%~n0.py" %* < NUL
+@"%EM_PY%" -E "%MYDIR%%~n0.py" %* < NUL
 @exit /b %ERRORLEVEL%
 
 :MUTE_STDIN_EXIT
-@"%EM_PY%" -E "%~dp0\%~n0.py" %* < NUL
+@"%EM_PY%" -E "%MYDIR%%~n0.py" %* < NUL
 @exit %ERRORLEVEL%
 
 :NORMAL
-@"%EM_PY%" -E "%~dp0\%~n0.py" %*
+@"%EM_PY%" -E "%MYDIR%%~n0.py" %*

emcc.bat

@@ -5,6 +5,9 @@
 :: To make modifications to this file, edit `tools/run_python_compiler.bat` and
 :: then run `tools/create_entry_points.py`
 
+:: N.b. In Windows .bat scripts, the ':' character cannot appear inside any if () blocks,
+:: or there will be a parsing error.
+
 :: All env. vars specified in this file are to be local only to this script.
 @setlocal
 :: -E will not ignore _PYTHON_SYSCONFIGDATA_NAME an internal
@@ -15,13 +18,34 @@
   set EM_PY=python
 )
 
+:: Work around Windows bug https://github.com/microsoft/terminal/issues/15212 : If this
+:: script is invoked via enclosing the invocation in quotes via PATH lookup, then %~f0 and
+:: %~dp0 expansions will not work.
+:: So first try if %~dp0 might work, and if not, manually look up this script from PATH.
+@if exist %~f0 (
+  set MYDIR=%~dp0
+  goto FOUND_MYDIR
+)
+@for %%I in (%~n0.bat) do (
+  @if exist %%~$PATH:I (
+    set MYDIR=%%~dp$PATH:I
+  ) else (
+    echo Fatal Error! Due to a Windows bug, we are unable to locate the path to %~n0.bat.
+    echo To help this issue, try removing unnecessary quotes in the invocation of emcc,
+    echo or add Emscripten directory to PATH.
+    echo See github.com/microsoft/terminal/issues/15212 and
+    echo github.com/emscripten-core/emscripten/issues/19207 for more details.
+  )
+)
+:FOUND_MYDIR
+
 :: If _EMCC_CCACHE is not set, do a regular invocation of the python compiler driver.
 :: Otherwise remove the ccache env. var, and then reinvoke this script with ccache enabled.
 @if "%_EMCC_CCACHE%"=="" (
-  set CMD="%EM_PY%" -E "%~dp0\%~n0.py"
+  set CMD="%EM_PY%" -E "%MYDIR%%~n0.py"
 ) else (
   set _EMCC_CCACHE=
-  set CMD=ccache "%~dp0\%~n0.bat"
+  set CMD=ccache "%MYDIR%%~n0.bat"
 )
 
 :: Python Windows bug https://bugs.python.org/issue34780: If this script was invoked via a

emcmake.bat

@@ -5,6 +5,9 @@
 :: To make modifications to this file, edit `tools/run_python.bat` and then run
 :: `tools/create_entry_points.py`
 
+:: N.b. In Windows .bat scripts, the ':' character cannot appear inside any if () blocks,
+:: or there will be a parsing error.
+
 :: All env. vars specified in this file are to be local only to this script.
 @setlocal
 :: -E will not ignore _PYTHON_SYSCONFIGDATA_NAME an internal
@@ -15,6 +18,27 @@
   set EM_PY=python
 )
 
+:: Work around Windows bug https://github.com/microsoft/terminal/issues/15212 : If this
+:: script is invoked via enclosing the invocation in quotes via PATH lookup, then %~f0 and
+:: %~dp0 expansions will not work.
+:: So first try if %~dp0 might work, and if not, manually look up this script from PATH.
+@if exist %~f0 (
+  set MYDIR=%~dp0
+  goto FOUND_MYDIR
+)
+@for %%I in (%~n0.bat) do (
+  @if exist %%~$PATH:I (
+    set MYDIR=%%~dp$PATH:I
+  ) else (
+    echo Fatal Error! Due to a Windows bug, we are unable to locate the path to %~n0.bat.
+    echo To help this issue, try removing unnecessary quotes in the invocation of emcc,
+    echo or add Emscripten directory to PATH.
+    echo See github.com/microsoft/terminal/issues/15212 and
+    echo github.com/emscripten-core/emscripten/issues/19207 for more details.
+  )
+)
+:FOUND_MYDIR
+
 :: Python Windows bug https://bugs.python.org/issue34780: If this script was invoked via a
 :: shared stdin handle from the parent process, and that parent process stdin handle is in
 :: a certain state, running python.exe might hang here. To work around this, if
@@ -47,16 +71,16 @@
 )
 
 :NORMAL_EXIT
-@"%EM_PY%" -E "%~dp0\%~n0.py" %*
+@"%EM_PY%" -E "%MYDIR%%~n0.py" %*
 @exit %ERRORLEVEL%
 
 :MUTE_STDIN
-@"%EM_PY%" -E "%~dp0\%~n0.py" %* < NUL
+@"%EM_PY%" -E "%MYDIR%%~n0.py" %* < NUL
 @exit /b %ERRORLEVEL%
 
 :MUTE_STDIN_EXIT
-@"%EM_PY%" -E "%~dp0\%~n0.py" %* < NUL
+@"%EM_PY%" -E "%MYDIR%%~n0.py" %* < NUL
 @exit %ERRORLEVEL%
 
 :NORMAL
-@"%EM_PY%" -E "%~dp0\%~n0.py" %*
+@"%EM_PY%" -E "%MYDIR%%~n0.py" %*

emconfigure.bat

@@ -5,6 +5,9 @@
 :: To make modifications to this file, edit `tools/run_python.bat` and then run
 :: `tools/create_entry_points.py`
 
+:: N.b. In Windows .bat scripts, the ':' character cannot appear inside any if () blocks,
+:: or there will be a parsing error.
+
 :: All env. vars specified in this file are to be local only to this script.
 @setlocal
 :: -E will not ignore _PYTHON_SYSCONFIGDATA_NAME an internal
@@ -15,6 +18,27 @@
   set EM_PY=python
 )
 
+:: Work around Windows bug https://github.com/microsoft/terminal/issues/15212 : If this
+:: script is invoked via enclosing the invocation in quotes via PATH lookup, then %~f0 and
+:: %~dp0 expansions will not work.
+:: So first try if %~dp0 might work, and if not, manually look up this script from PATH.
+@if exist %~f0 (
+  set MYDIR=%~dp0
+  goto FOUND_MYDIR
+)
+@for %%I in (%~n0.bat) do (
+  @if exist %%~$PATH:I (
+    set MYDIR=%%~dp$PATH:I
+  ) else (
+    echo Fatal Error! Due to a Windows bug, we are unable to locate the path to %~n0.bat.
+    echo To help this issue, try removing unnecessary quotes in the invocation of emcc,
+    echo or add Emscripten directory to PATH.
+    echo See github.com/microsoft/terminal/issues/15212 and
+    echo github.com/emscripten-core/emscripten/issues/19207 for more details.
+  )
+)
+:FOUND_MYDIR
+
 :: Python Windows bug https://bugs.python.org/issue34780: If this script was invoked via a
 :: shared stdin handle from the parent process, and that parent process stdin handle is in
 :: a certain state, running python.exe might hang here. To work around this, if
@@ -47,16 +71,16 @@
 )
 
 :NORMAL_EXIT
-@"%EM_PY%" -E "%~dp0\%~n0.py" %*
+@"%EM_PY%" -E "%MYDIR%%~n0.py" %*
 @exit %ERRORLEVEL%
 
 :MUTE_STDIN
-@"%EM_PY%" -E "%~dp0\%~n0.py" %* < NUL
+@"%EM_PY%" -E "%MYDIR%%~n0.py" %* < NUL
 @exit /b %ERRORLEVEL%
 
 :MUTE_STDIN_EXIT
-@"%EM_PY%" -E "%~dp0\%~n0.py" %* < NUL
+@"%EM_PY%" -E "%MYDIR%%~n0.py" %* < NUL
 @exit %ERRORLEVEL%
 
 :NORMAL
-@"%EM_PY%" -E "%~dp0\%~n0.py" %*
+@"%EM_PY%" -E "%MYDIR%%~n0.py" %*