sysdir: move windows sysdir functions out of shared util

The windows sysdir functions are libgit2-specific and for git
compatibility only; remove them from the shared util directory and bring
them into the libgit2 source tree.

Author: ethomson

src/libgit2/sysdir.c

@@ -12,16 +12,262 @@
 #include "fs_path.h"
 #include <ctype.h>
 #if GIT_WIN32
-#include "win32/findfile.h"
+# include "fs_path.h"
+# include "win32/path_w32.h"
+# include "win32/utf-conv.h"
 #else
-#include <unistd.h>
-#include <pwd.h>
+# include <unistd.h>
+# include <pwd.h>
 #endif
 
+#ifdef GIT_WIN32
+# define REG_GITFORWINDOWS_KEY       L"SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Uninstall\\Git_is1"
+# define REG_GITFORWINDOWS_KEY_WOW64 L"SOFTWARE\\Wow6432Node\\Microsoft\\Windows\\CurrentVersion\\Uninstall\\Git_is1"
+
+static int expand_win32_path(git_win32_path dest, const wchar_t *src)
+{
+	DWORD len = ExpandEnvironmentStringsW(src, dest, GIT_WIN_PATH_UTF16);
+
+	if (!len || len > GIT_WIN_PATH_UTF16)
+		return -1;
+
+	return 0;
+}
+
+static int win32_path_to_utf8(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 git_win32_path mock_registry;
+static bool mock_registry_set;
+
+extern int git_win32__set_registry_system_dir(const wchar_t *mock_sysdir)
+{
+	if (!mock_sysdir) {
+		mock_registry[0] = L'\0';
+		mock_registry_set = false;
+	} else {
+		size_t len = wcslen(mock_sysdir);
+
+		if (len > GIT_WIN_PATH_MAX) {
+			git_error_set(GIT_ERROR_INVALID, "mock path too long");
+			return -1;
+		}
+
+		wcscpy(mock_registry, mock_sysdir);
+		mock_registry_set = true;
+	}
+
+	return 0;
+}
+
+static int lookup_registry_key(
+	git_win32_path out,
+	const HKEY hive,
+	const wchar_t* key,
+	const wchar_t *value)
+{
+	HKEY hkey;
+	DWORD type, size;
+	int error = GIT_ENOTFOUND;
+
+	/*
+	 * Registry data may not be NUL terminated, provide room to do
+	 * it ourselves.
+	 */
+	size = (DWORD)((sizeof(git_win32_path) - 1) * sizeof(wchar_t));
+
+	if (RegOpenKeyExW(hive, key, 0, KEY_READ, &hkey) != 0)
+		return GIT_ENOTFOUND;
+
+	if (RegQueryValueExW(hkey, value, NULL, &type, (LPBYTE)out, &size) == 0 &&
+	    type == REG_SZ &&
+	    size > 0 &&
+	    size < sizeof(git_win32_path)) {
+		size_t wsize = size / sizeof(wchar_t);
+		size_t len = wsize - 1;
+
+		if (out[wsize - 1] != L'\0') {
+			len = wsize;
+			out[wsize] = L'\0';
+		}
+
+		if (out[len - 1] == L'\\')
+			out[len - 1] = L'\0';
+
+		if (_waccess(out, F_OK) == 0)
+			error = 0;
+	}
+
+	RegCloseKey(hkey);
+	return error;
+}
+
+static int find_sysdir_in_registry(git_win32_path out)
+{
+	if (mock_registry_set) {
+		if (mock_registry[0] == L'\0')
+			return GIT_ENOTFOUND;
+
+		wcscpy(out, mock_registry);
+		return 0;
+	}
+
+	if (lookup_registry_key(out, HKEY_CURRENT_USER, REG_GITFORWINDOWS_KEY, L"InstallLocation") == 0 ||
+	    lookup_registry_key(out, HKEY_CURRENT_USER, REG_GITFORWINDOWS_KEY_WOW64, L"InstallLocation") == 0 ||
+	    lookup_registry_key(out, HKEY_LOCAL_MACHINE, REG_GITFORWINDOWS_KEY, L"InstallLocation") == 0 ||
+	    lookup_registry_key(out, HKEY_LOCAL_MACHINE, REG_GITFORWINDOWS_KEY_WOW64, L"InstallLocation") == 0)
+		return 0;
+
+    return GIT_ENOTFOUND;
+}
+
+static int find_sysdir_in_path(git_win32_path out)
+{
+	size_t out_len;
+
+	if (git_win32_path_find_executable(out, L"git.exe") < 0 &&
+	    git_win32_path_find_executable(out, L"git.cmd") < 0)
+		return GIT_ENOTFOUND;
+
+	out_len = wcslen(out);
+
+	/* Trim the file name */
+	if (out_len <= CONST_STRLEN(L"git.exe"))
+		return GIT_ENOTFOUND;
+
+	out_len -= CONST_STRLEN(L"git.exe");
+
+	if (out_len && out[out_len - 1] == L'\\')
+		out_len--;
+
+	/*
+	 * Git for Windows usually places the command in a 'bin' or
+	 * 'cmd' directory, trim that.
+	 */
+	if (out_len >= CONST_STRLEN(L"\\bin") &&
+	    wcsncmp(&out[out_len - CONST_STRLEN(L"\\bin")], L"\\bin", CONST_STRLEN(L"\\bin")) == 0)
+		out_len -= CONST_STRLEN(L"\\bin");
+	else if (out_len >= CONST_STRLEN(L"\\cmd") &&
+	         wcsncmp(&out[out_len - CONST_STRLEN(L"\\cmd")], L"\\cmd", CONST_STRLEN(L"\\cmd")) == 0)
+		out_len -= CONST_STRLEN(L"\\cmd");
+
+	if (!out_len)
+		return GIT_ENOTFOUND;
+
+	out[out_len] = L'\0';
+	return 0;
+}
+
+static int find_win32_dirs(
+    git_str *out,
+    const wchar_t* tmpl[])
+{
+	git_win32_path path16;
+	git_str buf = GIT_STR_INIT;
+
+	git_str_clear(out);
+
+	for (; *tmpl != NULL; tmpl++) {
+		if (!expand_win32_path(path16, *tmpl) &&
+		    path16[0] != L'%' &&
+		    !_waccess(path16, F_OK)) {
+			win32_path_to_utf8(&buf, path16);
+
+			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);
+}
+
+static int append_subdir(git_str *out, git_str *path, const char *subdir)
+{
+	static const char* architecture_roots[] = {
+		"",
+		"mingw64",
+		"mingw32",
+		NULL
+	};
+	const char **root;
+	size_t orig_path_len = path->size;
+
+	for (root = architecture_roots; *root; root++) {
+		if ((*root[0] && git_str_joinpath(path, path->ptr, *root) < 0) ||
+		    git_str_joinpath(path, path->ptr, subdir) < 0)
+			return -1;
+
+		if (git_fs_path_exists(path->ptr) &&
+		    git_str_join(out, GIT_PATH_LIST_SEPARATOR, out->ptr, path->ptr) < 0)
+			return -1;
+
+		git_str_truncate(path, orig_path_len);
+	}
+
+	return 0;
+}
+
+int git_win32__find_system_dirs(git_str *out, const char *subdir)
+{
+	git_win32_path pathdir, regdir;
+	git_str path8 = GIT_STR_INIT;
+	bool has_pathdir, has_regdir;
+	int error;
+
+	has_pathdir = (find_sysdir_in_path(pathdir) == 0);
+	has_regdir = (find_sysdir_in_registry(regdir) == 0);
+
+	if (!has_pathdir && !has_regdir)
+		return 0;
+
+	/*
+	 * Usually the git in the path is the same git in the registry,
+	 * in this case there's no need to duplicate the paths.
+	 */
+	if (has_pathdir && has_regdir && wcscmp(pathdir, regdir) == 0)
+		has_regdir = false;
+
+	if (has_pathdir) {
+		if ((error = win32_path_to_utf8(&path8, pathdir)) < 0 ||
+		    (error = append_subdir(out, &path8, subdir)) < 0)
+			goto done;
+	}
+
+	if (has_regdir) {
+		if ((error = win32_path_to_utf8(&path8, regdir)) < 0 ||
+		    (error = append_subdir(out, &path8, subdir)) < 0)
+			goto done;
+	}
+
+done:
+    git_str_dispose(&path8);
+    return error;
+}
+#endif /* WIN32 */
+
 static int git_sysdir_guess_programdata_dirs(git_str *out)
 {
 #ifdef GIT_WIN32
-	return git_win32__find_programdata_dirs(out);
+	static const wchar_t *programdata_tmpls[2] = {
+		L"%PROGRAMDATA%\\Git",
+		NULL,
+	};
+
+	return find_win32_dirs(out, programdata_tmpls);
 #else
 	git_str_clear(out);
 	return 0;
@@ -78,7 +324,14 @@ static int get_passwd_home(git_str *out, uid_t uid)
 static int git_sysdir_guess_global_dirs(git_str *out)
 {
 #ifdef GIT_WIN32
-	return git_win32__find_global_dirs(out);
+	static const wchar_t *global_tmpls[4] = {
+		L"%HOME%\\",
+		L"%HOMEDRIVE%%HOMEPATH%\\",
+		L"%USERPROFILE%\\",
+		NULL,
+	};
+
+	return find_win32_dirs(out, global_tmpls);
 #else
 	int error;
 	uid_t uid, euid;
@@ -117,7 +370,17 @@ static int git_sysdir_guess_global_dirs(git_str *out)
 static int git_sysdir_guess_xdg_dirs(git_str *out)
 {
 #ifdef GIT_WIN32
-	return git_win32__find_xdg_dirs(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 find_win32_dirs(out, global_tmpls);
 #else
 	git_str env = GIT_STR_INIT;
 	int error;

src/libgit2/sysdir.h

@@ -110,4 +110,10 @@ extern int git_sysdir_set(git_sysdir_t which, const char *paths);
  */
 extern int git_sysdir_reset(void);
 
+/** Sets the registry system dir to a mock; for testing.  */
+extern int git_win32__set_registry_system_dir(const wchar_t *mock_sysdir);
+
+/** Find the given system dir; for testing. */
+extern int git_win32__find_system_dirs(git_str *out, const char *subdir);
+
 #endif

src/util/futils.c

@@ -13,9 +13,6 @@
 #include "rand.h"
 
 #include <ctype.h>
-#if GIT_WIN32
-#include "win32/findfile.h"
-#endif
 
 #define GIT_FILEMODE_DEFAULT 0100666