thodg/libgit2/src/win32/findfile.c

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• Hash : 7fd5dfa0
  Author :
  Date : 2021-12-25T15:25:15
  

  Correctly detect the share/template folder
  
  With Git for Windows >= 2 the share folder is in an architecture specific subfolder.
  
  This also add support for Git for Windows versions between 2 and 2.24 where also the etc folder is in an architecture specific subfolder.
  
  Signed-off-by: Sven Strickroth <email@cs-ware.de>
  

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• src/win32/findfile.c

• /*
   * Copyright (C) the libgit2 contributors. All rights reserved.
   *
   * This file is part of libgit2, distributed under the GNU GPL v2 with
   * a Linking Exception. For full terms see the included COPYING file.
   */
  
  #include "findfile.h"
  
  #include "path_w32.h"
  #include "utf-conv.h"
  #include "fs_path.h"
  
  #define REG_MSYSGIT_INSTALL_LOCAL L"SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Uninstall\\Git_is1"
  
  #ifndef _WIN64
  #define REG_MSYSGIT_INSTALL REG_MSYSGIT_INSTALL_LOCAL
  #else
  #define REG_MSYSGIT_INSTALL L"SOFTWARE\\Wow6432Node\\Microsoft\\Windows\\CurrentVersion\\Uninstall\\Git_is1"
  #endif
  
  typedef struct {
  	git_win32_path path;
  	DWORD len;
  } _findfile_path;
  
  static int git_win32__expand_path(_findfile_path *dest, const wchar_t *src)
  {
  	dest->len = ExpandEnvironmentStringsW(src, dest->path, ARRAY_SIZE(dest->path));
  
  	if (!dest->len || dest->len > ARRAY_SIZE(dest->path))
  		return -1;
  
  	return 0;
  }
  
  static int win32_path_to_8(git_str *dest, const wchar_t *src)
  {
  	git_win32_utf8_path utf8_path;
  
  	if (git_win32_path_to_utf8(utf8_path, src) < 0) {
  		git_error_set(GIT_ERROR_OS, "unable to convert path to UTF-8");
  		return -1;
  	}
  
  	/* Convert backslashes to forward slashes */
  	git_fs_path_mkposix(utf8_path);
  
  	return git_str_sets(dest, utf8_path);
  }
  
  static wchar_t *win32_walkpath(wchar_t *path, wchar_t *buf, size_t buflen)
  {
  	wchar_t term, *base = path;
  
  	GIT_ASSERT_ARG_WITH_RETVAL(path, NULL);
  	GIT_ASSERT_ARG_WITH_RETVAL(buf, NULL);
  	GIT_ASSERT_ARG_WITH_RETVAL(buflen, NULL);
  
  	term = (*path == L'"') ? *path++ : L';';
  
  	for (buflen--; *path && *path != term && buflen; buflen--)
  		*buf++ = *path++;
  
  	*buf = L'\0'; /* reserved a byte via initial subtract */
  
  	while (*path == term || *path == L';')
  		path++;
  
  	return (path != base) ? path : NULL;
  }
  
  static int win32_find_git_for_windows_architecture_root(_findfile_path *root_path, const wchar_t *subdir)
  {
  	/* Git for Windows >= 2 comes with a special architecture root (mingw64 and mingw32)
  	 * under which the "share" folder is located, check which we need (none is also ok) */
  
  	static const wchar_t *architecture_roots[4] = {
  		L"", // starting with Git 2.24 the etc folder is directly in the root folder
  		L"mingw64\\",
  		L"mingw32\\",
  		NULL,
  	};
  
  	const wchar_t **roots = architecture_roots;
  	for (; *roots != NULL; ++roots) {
  		git_win32_path tmp_root;
  		DWORD subdir_len;
  		if (wcscpy(tmp_root, root_path->path) &&
  			root_path->len + wcslen(*roots) <= MAX_PATH &&
  			wcscat(tmp_root, *roots) &&
  			!_waccess(tmp_root, F_OK)) {
  			wcscpy(root_path->path, tmp_root);
  			root_path->len += (DWORD)wcslen(*roots);
  
  			subdir_len = (DWORD)wcslen(subdir);
  			if (root_path->len + subdir_len >= MAX_PATH)
  				break;
  
  			// append subdir and check whether it exists for the Git installation
  			wcscat(tmp_root, subdir);
  			if (!_waccess(tmp_root, F_OK)) {
  				wcscpy(root_path->path, tmp_root);
  				root_path->len += subdir_len;
  				break;
  			}
  		}
  	}
  
  	return 0;
  }
  
  static int win32_find_git_in_path(git_str *buf, const wchar_t *gitexe, const wchar_t *subdir)
  {
  	wchar_t *env = _wgetenv(L"PATH"), lastch;
  	_findfile_path root;
  	size_t gitexe_len = wcslen(gitexe);
  
  	if (!env)
  		return -1;
  
  	while ((env = win32_walkpath(env, root.path, MAX_PATH-1)) && *root.path) {
  		root.len = (DWORD)wcslen(root.path);
  		lastch = root.path[root.len - 1];
  
  		/* ensure trailing slash (MAX_PATH-1 to walkpath guarantees space) */
  		if (lastch != L'/' && lastch != L'\\') {
  			root.path[root.len++] = L'\\';
  			root.path[root.len]   = L'\0';
  		}
  
  		if (root.len + gitexe_len >= MAX_PATH)
  			continue;
  		wcscpy(&root.path[root.len], gitexe);
  
  		if (!_waccess(root.path, F_OK)) {
  			/* check whether we found a Git for Windows installation and do some path adjustments OR just append subdir */
  			if ((root.len > 5 && wcscmp(root.path - 4, L"cmd\\")) || wcscmp(root.path - 4, L"bin\\")) {
  				/* strip "bin" or "cmd" and try to find architecture root for appending subdir */
  				root.len -= 4;
  				root.path[root.len] = L'\0';
  				if (win32_find_git_for_windows_architecture_root(&root, subdir))
  					continue;
  			} else {
  				if (root.len + wcslen(subdir) >= MAX_PATH)
  					continue;
  				wcscat(root.path, subdir);
  			}
  
  			win32_path_to_8(buf, root.path);
  			return 0;
  		}
  	}
  
  	return GIT_ENOTFOUND;
  }
  
  static int win32_find_git_in_registry(
  	git_str *buf, const HKEY hive, const wchar_t *key, const wchar_t *subdir)
  {
  	HKEY hKey;
  	int error = GIT_ENOTFOUND;
  
  	GIT_ASSERT_ARG(buf);
  
  	if (!RegOpenKeyExW(hive, key, 0, KEY_READ, &hKey)) {
  		DWORD dwType, cbData;
  		_findfile_path path;
  
  		/* Ensure that the buffer is big enough to have the suffix attached
  		 * after we receive the result. */
  		cbData = (DWORD)(sizeof(path) - wcslen(subdir) * sizeof(wchar_t));
  
  		/* InstallLocation points to the root of the git directory */
  		if (!RegQueryValueExW(hKey, L"InstallLocation", NULL, &dwType, (LPBYTE)path.path, &cbData) &&
  			dwType == REG_SZ) {
  			path.len = cbData;
  
  			/* Convert to UTF-8, with forward slashes, and output the path
  			 * to the provided buffer */
  			if (!win32_find_git_for_windows_architecture_root(&path, subdir) &&
  				!win32_path_to_8(buf, path.path))
  				error = 0;
  		}
  
  		RegCloseKey(hKey);
  	}
  
  	return error;
  }
  
  static int win32_find_existing_dirs(
  	git_str *out, const wchar_t *tmpl[])
  {
  	_findfile_path path16;
  	git_str buf = GIT_STR_INIT;
  
  	git_str_clear(out);
  
  	for (; *tmpl != NULL; tmpl++) {
  		if (!git_win32__expand_path(&path16, *tmpl) &&
  			path16.path[0] != L'%' &&
  			!_waccess(path16.path, F_OK))
  		{
  			win32_path_to_8(&buf, path16.path);
  
  			if (buf.size)
  				git_str_join(out, GIT_PATH_LIST_SEPARATOR, out->ptr, buf.ptr);
  		}
  	}
  
  	git_str_dispose(&buf);
  
  	return (git_str_oom(out) ? -1 : 0);
  }
  
  int git_win32__find_system_dirs(git_str *out, const wchar_t *subdir)
  {
  	git_str buf = GIT_STR_INIT;
  
  	/* directories where git.exe & git.cmd are found */
  	if (!win32_find_git_in_path(&buf, L"git.exe", subdir) && buf.size)
  		git_str_set(out, buf.ptr, buf.size);
  	else
  		git_str_clear(out);
  
  	if (!win32_find_git_in_path(&buf, L"git.cmd", subdir) && buf.size)
  		git_str_join(out, GIT_PATH_LIST_SEPARATOR, out->ptr, buf.ptr);
  
  	/* directories where git is installed according to registry */
  	if (!win32_find_git_in_registry(
  			&buf, HKEY_CURRENT_USER, REG_MSYSGIT_INSTALL_LOCAL, subdir) && buf.size)
  		git_str_join(out, GIT_PATH_LIST_SEPARATOR, out->ptr, buf.ptr);
  
  #ifdef GIT_ARCH_64
  	if (!win32_find_git_in_registry(
  			&buf, HKEY_LOCAL_MACHINE, REG_MSYSGIT_INSTALL_LOCAL, subdir) && buf.size)
  		git_str_join(out, GIT_PATH_LIST_SEPARATOR, out->ptr, buf.ptr);
  #endif
  
  	if (!win32_find_git_in_registry(
  			&buf, HKEY_LOCAL_MACHINE, REG_MSYSGIT_INSTALL, subdir) && buf.size)
  		git_str_join(out, GIT_PATH_LIST_SEPARATOR, out->ptr, buf.ptr);
  
  	git_str_dispose(&buf);
  
  	return (git_str_oom(out) ? -1 : 0);
  }
  
  int git_win32__find_global_dirs(git_str *out)
  {
  	static const wchar_t *global_tmpls[4] = {
  		L"%HOME%\\",
  		L"%HOMEDRIVE%%HOMEPATH%\\",
  		L"%USERPROFILE%\\",
  		NULL,
  	};
  
  	return win32_find_existing_dirs(out, global_tmpls);
  }
  
  int git_win32__find_xdg_dirs(git_str *out)
  {
  	static const wchar_t *global_tmpls[7] = {
  		L"%XDG_CONFIG_HOME%\\git",
  		L"%APPDATA%\\git",
  		L"%LOCALAPPDATA%\\git",
  		L"%HOME%\\.config\\git",
  		L"%HOMEDRIVE%%HOMEPATH%\\.config\\git",
  		L"%USERPROFILE%\\.config\\git",
  		NULL,
  	};
  
  	return win32_find_existing_dirs(out, global_tmpls);
  }
  
  int git_win32__find_programdata_dirs(git_str *out)
  {
  	static const wchar_t *programdata_tmpls[2] = {
  		L"%PROGRAMDATA%\\Git",
  		NULL,
  	};
  
  	return win32_find_existing_dirs(out, programdata_tmpls);
  }
  

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