membrane.cmd uses current directory instead of script directory

[coderabbitai]

Issue Description

The Windows batch script distribution/examples/xml/namespaces/membrane.cmd uses %CD% to set the initial directory, which resolves to the current working directory where the script is executed from, not the directory where the script is located.

This differs from the POSIX script (membrane.sh) which correctly uses the script's own directory. If a user runs this script from a different directory (e.g., C:\other\path> C:\membrane\examples\xml\namespaces\membrane.cmd), the upward traversal will start from C:\other\path instead of the script's location, causing it to fail to locate the Membrane root.

Affected File

• distribution/examples/xml/namespaces/membrane.cmd (line 3)

Expected Behavior

The script should use %~dp0 to get the script's own directory, similar to how membrane.sh uses the script's directory.

Related PR

• Pull Request: XML Namespace Declarations for XPath Expressions #2253
• Review Comment: XML Namespace Declarations for XPath Expressions #2253 (comment)

Reported by: @predic8

[predic8]

@coderabbitai can u suggest solution here?

[coderabbitai]

Tip

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🧩 Analysis chain

🏁 Script executed:

#!/bin/bash
# Read the affected Windows batch script
echo "=== Content of membrane.cmd ==="
cat distribution/examples/xml/namespaces/membrane.cmd

echo -e "\n=== Content of membrane.sh for comparison ==="
cat distribution/examples/xml/namespaces/membrane.sh

Length of output: 241

---

🏁 Script executed:

#!/bin/bash
# Search for membrane.cmd and membrane.sh files
echo "=== Searching for membrane.cmd files ==="
fd -t f "membrane.cmd"

echo -e "\n=== Searching for membrane.sh files ==="
fd -t f "membrane.sh"

Length of output: 13080

---

🏁 Script executed:

#!/bin/bash
# Read a representative membrane.cmd file to see the issue
echo "=== Content of distribution/examples/xml/xslt/membrane.cmd ==="
cat distribution/examples/xml/xslt/membrane.cmd

echo -e "\n=== Content of corresponding membrane.sh ==="
cat distribution/examples/xml/xslt/membrane.sh

Length of output: 1376

---

@predic8 Sure! The issue is on line 3 of the membrane.cmd files. Here's the fix:

Current Problem

set "dir=%CD%"

This uses %CD% which resolves to the current working directory (where the user runs the command from), not the script's directory.

Solution

Replace line 3 with:

set "dir=%~dp0"

The %~dp0 expands to the drive and path of the script itself:

• %0 = the script
• ~ = remove quotes
• d = drive letter
• p = path

This matches the behavior of the POSIX script, which correctly uses SCRIPT_DIR=$(CDPATH= cd -- "$(dirname -- "$0")" && pwd -P) to get the script's own directory before starting the upward traversal.

Complete Fixed Version

@echo off
setlocal
set "dir=%~dp0"
:loop
if exist "%dir%\starter.jar" if exist "%dir%\scripts\run-membrane.cmd" goto found
for %%A in ("%dir%\..") do set "next=%%~fA"
if /I "%next%"=="%dir%" goto notfound
set "dir=%next%"
if "%dir%"=="%SystemDrive%\" goto notfound
goto loop
:found
set "ROOT=%dir%"
call "%ROOT%\scripts\run-membrane.cmd" %*
exit /b %ERRORLEVEL%
:notfound
>&2 echo Could not locate Membrane root. Ensure directory structure is correct.
exit /b 1

This fix should be applied to all affected membrane.cmd files throughout the repository to ensure consistency with the POSIX shell scripts.

---

🧠 Learnings used

Learnt from: rrayst
Repo: membrane/api-gateway PR: 1947
File: distribution/tutorials/soap/membrane.sh:17-22
Timestamp: 2025-07-02T18:05:47.059Z
Learning: When using environment variable shortcuts like `$MEMBRANE_HOME` in shell scripts that look for installation directories, validate that required files (like `starter.jar` for Membrane) exist in the candidate directory before returning it. This prevents hard-to-diagnose runtime errors when the environment variable points to an invalid or stale location.