prompt: We are currently solving the following issue within our repository. Here is the issue text:
  --- BEGIN ISSUE ---
  local cache inconsistent after enabling short_paths in a recipe
  To help us debug your issue please explain:
  
  - [x] I've read the [CONTRIBUTING guide](https://raw.githubusercontent.com/conan-io/conan/develop/.github/CONTRIBUTING.md).
  - [x] I've specified the Conan version, operating system version and any tool that can be relevant.
  - [x] I've explained the steps to reproduce the error or the motivation/use case of the question/suggestion.
  
  Conan Version 1.3.3
  Windows 10
  
  With a package in local cache whose recipe does NOT have `short_paths=True`, modify in normal development folder the recipe and set `short_paths=True` and run conan create.
  
  Folders in local cache become inconsistent showing both folders from previous conan create run and .conan_link files pointing to the short paths folders.
  
  This seems no not affect conan tool behavior when running commands and works well if `short_paths` is removed once again.
  
  
  
  --- END ISSUE ---
  
  Below are some code segments, each from a relevant file. One or more of these files may contain bugs.
  --- BEGIN FILES ---
  Path: `conans/util/windows.py`
  Content:
  ```
  1 import os
  2 import subprocess
  3 
  4 from conans.util.files import load, mkdir, save, rmdir
  5 import tempfile
  6 
  7 
  8 CONAN_LINK = ".conan_link"
  9 
  10 
  11 def conan_expand_user(path):
  12     """ wrapper to the original expanduser function, to workaround python returning
  13     verbatim %USERPROFILE% when some other app (git for windows) sets HOME envvar
  14     """
  15     # In win these variables should exist and point to user directory, which
  16     # must exist. Using context to avoid permanent modification of os.environ
  17     old_env = dict(os.environ)
  18     try:
  19         home = os.environ.get("HOME")
  20         # Problematic cases of wrong HOME variable
  21         # - HOME = %USERPROFILE% verbatim, as messed by some other tools
  22         # - MSYS console, that defines a different user home in /c/mingw/msys/users/xxx
  23         # In these cases, it is safe to remove it and rely on USERPROFILE directly
  24         if home and (not os.path.exists(home) or
  25                      (os.getenv("MSYSTEM") and os.getenv("USERPROFILE"))):
  26             del os.environ["HOME"]
  27         result = os.path.expanduser(path)
  28     finally:
  29         os.environ.clear()
  30         os.environ.update(old_env)
  31     return result
  32 
  33 
  34 def path_shortener(path, short_paths):
  35     """ short_paths is 4-state:
  36     False: Never shorten the path
  37     True: Always shorten the path, create link if not existing
  38     None: Use shorten path only if already exists, not create
  39     """
  40     if short_paths is False or os.getenv("CONAN_USER_HOME_SHORT") == "None":
  41         return path
  42     link = os.path.join(path, CONAN_LINK)
  43     if os.path.exists(link):
  44         return load(link)
  45     elif short_paths is None:
  46         return path
  47 
  48     short_home = os.getenv("CONAN_USER_HOME_SHORT")
  49     if not short_home:
  50         drive = os.path.splitdrive(path)[0]
  51         short_home = drive + "/.conan"
  52     mkdir(short_home)
  53 
  54     # Workaround for short_home living in NTFS file systems. Give full control permission to current user to avoid
  55     # access problems in cygwin/msys2 windows subsystems when using short_home folder
  56     try:
  57         username = os.getenv("USERDOMAIN")
  58         domainname = "%s\%s" % (username, os.environ["USERNAME"]) if username else os.environ["USERNAME"]
  59         cmd = r'cacls %s /E /G "%s":F' % (short_home, domainname)
  60         subprocess.check_output(cmd, stderr=subprocess.STDOUT)  # Ignoring any returned output, make command quiet
  61     except subprocess.CalledProcessError:
  62         # cmd can fail if trying to set ACL in non NTFS drives, ignoring it.
  63         pass
  64 
  65     redirect = tempfile.mkdtemp(dir=short_home, prefix="")
  66     # This "1" is the way to have a non-existing directory, so commands like
  67     # shutil.copytree() to it, works. It can be removed without compromising the
  68     # temp folder generator and conan-links consistency
  69     redirect = os.path.join(redirect, "1")
  70     save(link, redirect)
  71     return redirect
  72 
  73 
  74 def ignore_long_path_files(src_folder, build_folder, output):
  75     def _filter(src, files):
  76         filtered_files = []
  77         for the_file in files:
  78             source_path = os.path.join(src, the_file)
  79             # Without storage path, just relative
  80             rel_path = os.path.relpath(source_path, src_folder)
  81             dest_path = os.path.normpath(os.path.join(build_folder, rel_path))
  82             # it is NOT that "/" is counted as "\\" so it counts double
  83             # seems a bug in python, overflows paths near the limit of 260,
  84             if len(dest_path) >= 249:
  85                 filtered_files.append(the_file)
  86                 output.warn("Filename too long, file excluded: %s" % dest_path)
  87         return filtered_files
  88     return _filter
  89 
  90 
  91 def rm_conandir(path):
  92     """removal of a directory that might contain a link to a short path"""
  93     link = os.path.join(path, CONAN_LINK)
  94     if os.path.exists(link):
  95         short_path = load(link)
  96         rmdir(os.path.dirname(short_path))
  97     rmdir(path)
  98
  ```
  --- END FILES ---
  
  Please first localize the bug based on the issue statement, and then generate a patch according to the `git diff` format fenced by three backticks.
  
  Here is an example:
  
  ```diff
  diff --git a/examples/server_async.py b/examples/server_async.py
  --- a/examples/server_async.py
  +++ b/examples/server_async.py
  @@ -313,4 +313,4 @@
   
   
   if __name__ == "__main__":
  -    asyncio.run(run_async_server("."), debug=True)
  +    asyncio.run(run_async_server(), debug=True)
  diff --git a/examples/server_sync.py b/examples/server_sync.py
  --- a/examples/server_sync.py
  +++ b/examples/server_sync.py
  @@ -313,5 +313,5 @@
   
   
   if __name__ == "__main__":
  -    server = run_sync_server(".")
  +    server = run_sync_server()
       server.shutdown()
  
  ```
  
golden_diff: diff --git a/conans/util/windows.py b/conans/util/windows.py
  --- a/conans/util/windows.py
  +++ b/conans/util/windows.py
  @@ -45,6 +45,9 @@
       elif short_paths is None:
           return path
   
  +    if os.path.exists(path):
  +        rmdir(path)
  +
       short_home = os.getenv("CONAN_USER_HOME_SHORT")
       if not short_home:
           drive = os.path.splitdrive(path)[0]
  
verification_info: {"golden_diff": "diff --git a/conans/util/windows.py b/conans/util/windows.py\n--- a/conans/util/windows.py\n+++ b/conans/util/windows.py\n@@ -45,6 +45,9 @@\n     elif short_paths is None:\n         return path\n \n+    if os.path.exists(path):\n+        rmdir(path)\n+\n     short_home = os.getenv(\"CONAN_USER_HOME_SHORT\")\n     if not short_home:\n         drive = os.path.splitdrive(path)[0]\n", "issue": "local cache inconsistent after enabling short_paths in a recipe\nTo help us debug your issue please explain:\r\n\r\n- [x] I've read the [CONTRIBUTING guide](https://raw.githubusercontent.com/conan-io/conan/develop/.github/CONTRIBUTING.md).\r\n- [x] I've specified the Conan version, operating system version and any tool that can be relevant.\r\n- [x] I've explained the steps to reproduce the error or the motivation/use case of the question/suggestion.\r\n\r\nConan Version 1.3.3\r\nWindows 10\r\n\r\nWith a package in local cache whose recipe does NOT have `short_paths=True`, modify in normal development folder the recipe and set `short_paths=True` and run conan create.\r\n\r\nFolders in local cache become inconsistent showing both folders from previous conan create run and .conan_link files pointing to the short paths folders.\r\n\r\nThis seems no not affect conan tool behavior when running commands and works well if `short_paths` is removed once again.\r\n\r\n\n", "before_files": [{"content": "import os\nimport subprocess\n\nfrom conans.util.files import load, mkdir, save, rmdir\nimport tempfile\n\n\nCONAN_LINK = \".conan_link\"\n\n\ndef conan_expand_user(path):\n    \"\"\" wrapper to the original expanduser function, to workaround python returning\n    verbatim %USERPROFILE% when some other app (git for windows) sets HOME envvar\n    \"\"\"\n    # In win these variables should exist and point to user directory, which\n    # must exist. Using context to avoid permanent modification of os.environ\n    old_env = dict(os.environ)\n    try:\n        home = os.environ.get(\"HOME\")\n        # Problematic cases of wrong HOME variable\n        # - HOME = %USERPROFILE% verbatim, as messed by some other tools\n        # - MSYS console, that defines a different user home in /c/mingw/msys/users/xxx\n        # In these cases, it is safe to remove it and rely on USERPROFILE directly\n        if home and (not os.path.exists(home) or\n                     (os.getenv(\"MSYSTEM\") and os.getenv(\"USERPROFILE\"))):\n            del os.environ[\"HOME\"]\n        result = os.path.expanduser(path)\n    finally:\n        os.environ.clear()\n        os.environ.update(old_env)\n    return result\n\n\ndef path_shortener(path, short_paths):\n    \"\"\" short_paths is 4-state:\n    False: Never shorten the path\n    True: Always shorten the path, create link if not existing\n    None: Use shorten path only if already exists, not create\n    \"\"\"\n    if short_paths is False or os.getenv(\"CONAN_USER_HOME_SHORT\") == \"None\":\n        return path\n    link = os.path.join(path, CONAN_LINK)\n    if os.path.exists(link):\n        return load(link)\n    elif short_paths is None:\n        return path\n\n    short_home = os.getenv(\"CONAN_USER_HOME_SHORT\")\n    if not short_home:\n        drive = os.path.splitdrive(path)[0]\n        short_home = drive + \"/.conan\"\n    mkdir(short_home)\n\n    # Workaround for short_home living in NTFS file systems. Give full control permission to current user to avoid\n    # access problems in cygwin/msys2 windows subsystems when using short_home folder\n    try:\n        username = os.getenv(\"USERDOMAIN\")\n        domainname = \"%s\\%s\" % (username, os.environ[\"USERNAME\"]) if username else os.environ[\"USERNAME\"]\n        cmd = r'cacls %s /E /G \"%s\":F' % (short_home, domainname)\n        subprocess.check_output(cmd, stderr=subprocess.STDOUT)  # Ignoring any returned output, make command quiet\n    except subprocess.CalledProcessError:\n        # cmd can fail if trying to set ACL in non NTFS drives, ignoring it.\n        pass\n\n    redirect = tempfile.mkdtemp(dir=short_home, prefix=\"\")\n    # This \"1\" is the way to have a non-existing directory, so commands like\n    # shutil.copytree() to it, works. It can be removed without compromising the\n    # temp folder generator and conan-links consistency\n    redirect = os.path.join(redirect, \"1\")\n    save(link, redirect)\n    return redirect\n\n\ndef ignore_long_path_files(src_folder, build_folder, output):\n    def _filter(src, files):\n        filtered_files = []\n        for the_file in files:\n            source_path = os.path.join(src, the_file)\n            # Without storage path, just relative\n            rel_path = os.path.relpath(source_path, src_folder)\n            dest_path = os.path.normpath(os.path.join(build_folder, rel_path))\n            # it is NOT that \"/\" is counted as \"\\\\\" so it counts double\n            # seems a bug in python, overflows paths near the limit of 260,\n            if len(dest_path) >= 249:\n                filtered_files.append(the_file)\n                output.warn(\"Filename too long, file excluded: %s\" % dest_path)\n        return filtered_files\n    return _filter\n\n\ndef rm_conandir(path):\n    \"\"\"removal of a directory that might contain a link to a short path\"\"\"\n    link = os.path.join(path, CONAN_LINK)\n    if os.path.exists(link):\n        short_path = load(link)\n        rmdir(os.path.dirname(short_path))\n    rmdir(path)\n", "path": "conans/util/windows.py"}], "after_files": [{"content": "import os\nimport subprocess\n\nfrom conans.util.files import load, mkdir, save, rmdir\nimport tempfile\n\n\nCONAN_LINK = \".conan_link\"\n\n\ndef conan_expand_user(path):\n    \"\"\" wrapper to the original expanduser function, to workaround python returning\n    verbatim %USERPROFILE% when some other app (git for windows) sets HOME envvar\n    \"\"\"\n    # In win these variables should exist and point to user directory, which\n    # must exist. Using context to avoid permanent modification of os.environ\n    old_env = dict(os.environ)\n    try:\n        home = os.environ.get(\"HOME\")\n        # Problematic cases of wrong HOME variable\n        # - HOME = %USERPROFILE% verbatim, as messed by some other tools\n        # - MSYS console, that defines a different user home in /c/mingw/msys/users/xxx\n        # In these cases, it is safe to remove it and rely on USERPROFILE directly\n        if home and (not os.path.exists(home) or\n                     (os.getenv(\"MSYSTEM\") and os.getenv(\"USERPROFILE\"))):\n            del os.environ[\"HOME\"]\n        result = os.path.expanduser(path)\n    finally:\n        os.environ.clear()\n        os.environ.update(old_env)\n    return result\n\n\ndef path_shortener(path, short_paths):\n    \"\"\" short_paths is 4-state:\n    False: Never shorten the path\n    True: Always shorten the path, create link if not existing\n    None: Use shorten path only if already exists, not create\n    \"\"\"\n    if short_paths is False or os.getenv(\"CONAN_USER_HOME_SHORT\") == \"None\":\n        return path\n    link = os.path.join(path, CONAN_LINK)\n    if os.path.exists(link):\n        return load(link)\n    elif short_paths is None:\n        return path\n\n    if os.path.exists(path):\n        rmdir(path)\n\n    short_home = os.getenv(\"CONAN_USER_HOME_SHORT\")\n    if not short_home:\n        drive = os.path.splitdrive(path)[0]\n        short_home = drive + \"/.conan\"\n    mkdir(short_home)\n\n    # Workaround for short_home living in NTFS file systems. Give full control permission to current user to avoid\n    # access problems in cygwin/msys2 windows subsystems when using short_home folder\n    try:\n        username = os.getenv(\"USERDOMAIN\")\n        domainname = \"%s\\%s\" % (username, os.environ[\"USERNAME\"]) if username else os.environ[\"USERNAME\"]\n        cmd = r'cacls %s /E /G \"%s\":F' % (short_home, domainname)\n        subprocess.check_output(cmd, stderr=subprocess.STDOUT)  # Ignoring any returned output, make command quiet\n    except subprocess.CalledProcessError:\n        # cmd can fail if trying to set ACL in non NTFS drives, ignoring it.\n        pass\n\n    redirect = tempfile.mkdtemp(dir=short_home, prefix=\"\")\n    # This \"1\" is the way to have a non-existing directory, so commands like\n    # shutil.copytree() to it, works. It can be removed without compromising the\n    # temp folder generator and conan-links consistency\n    redirect = os.path.join(redirect, \"1\")\n    save(link, redirect)\n    return redirect\n\n\ndef ignore_long_path_files(src_folder, build_folder, output):\n    def _filter(src, files):\n        filtered_files = []\n        for the_file in files:\n            source_path = os.path.join(src, the_file)\n            # Without storage path, just relative\n            rel_path = os.path.relpath(source_path, src_folder)\n            dest_path = os.path.normpath(os.path.join(build_folder, rel_path))\n            # it is NOT that \"/\" is counted as \"\\\\\" so it counts double\n            # seems a bug in python, overflows paths near the limit of 260,\n            if len(dest_path) >= 249:\n                filtered_files.append(the_file)\n                output.warn(\"Filename too long, file excluded: %s\" % dest_path)\n        return filtered_files\n    return _filter\n\n\ndef rm_conandir(path):\n    \"\"\"removal of a directory that might contain a link to a short path\"\"\"\n    link = os.path.join(path, CONAN_LINK)\n    if os.path.exists(link):\n        short_path = load(link)\n        rmdir(os.path.dirname(short_path))\n    rmdir(path)\n", "path": "conans/util/windows.py"}]}