git-wrapper: prepare for executing configurable command-lines

We are about to use the Git wrapper to call the Git Bash of Git for
Windows. All the wrapper needs to do for that is to set up the
environment variables, use the home directory as working directory and
then hand off to a user-specified command-line.

We prepare the existing code for this change by introducing flags to set
up the environment variables, to launch a non-Git program, and to use
the home directory as working directory.

Signed-off-by: Johannes Schindelin <[email protected]>

Author: dscho

compat/win32/git-wrapper.c

@@ -116,7 +116,7 @@ static void setup_environment(LPWSTR exepath)
  * untouched.
  */
 static LPWSTR fixup_commandline(LPWSTR exepath, LPWSTR *exep, int *wait,
-	LPWSTR prefix_args, int prefix_args_len)
+	LPWSTR prefix_args, int prefix_args_len, int is_git_command)
 {
 	int wargc = 0, gui = 0;
 	LPWSTR cmd = NULL, cmdline = NULL;
@@ -146,9 +146,14 @@ static LPWSTR fixup_commandline(LPWSTR exepath, LPWSTR *exep, int *wait,
 			*exep = NULL;
 		}
 	}
-	else if (prefix_args)
-		_swprintf(cmd, L"%s\\%s %.*s",
-			exepath, L"git.exe", prefix_args_len, prefix_args);
+	else if (prefix_args) {
+		if (is_git_command)
+			_swprintf(cmd, L"%s\\%s %.*s", exepath, L"git.exe",
+					prefix_args_len, prefix_args);
+		else
+			_swprintf(cmd, L"%.*s", prefix_args_len, prefix_args);
+
+	}
 	else
 		wcscpy(cmd, L"git.exe");
 
@@ -170,9 +175,10 @@ static LPWSTR fixup_commandline(LPWSTR exepath, LPWSTR *exep, int *wait,
 
 int main(void)
 {
-	int r = 1, wait = 1, prefix_args_len = -1;
+	int r = 1, wait = 1, prefix_args_len = -1, needs_env_setup = 1,
+		is_git_command = 1, start_in_home = 0;
 	WCHAR exepath[MAX_PATH], exe[MAX_PATH];
-	LPWSTR cmd = NULL, exep = exe, prefix_args = NULL, basename;
+	LPWSTR cmd = NULL, dir = NULL, exep = exe, prefix_args = NULL, basename;
 	UINT codepage = 0;
 
 	/* Determine MSys2-based Git path. */
@@ -187,6 +193,8 @@ int main(void)
 	}
 	basename = exepath + wcslen(exepath) + 1;
 	if (!wcsncmp(basename, L"git-", 4)) {
+		needs_env_setup = 0;
+
 		/* Call a builtin */
 		prefix_args = basename + 4;
 		prefix_args_len = wcslen(prefix_args);
@@ -214,10 +222,19 @@ int main(void)
 		}
 	}
 
-	if (!prefix_args)
+	if (needs_env_setup)
 		setup_environment(exepath);
 	cmd = fixup_commandline(exepath, &exep, &wait,
-		prefix_args, prefix_args_len);
+		prefix_args, prefix_args_len, is_git_command);
+
+	if (start_in_home) {
+		int len = GetEnvironmentVariable(L"HOME", NULL, 0);
+
+		if (len) {
+			dir = malloc(sizeof(WCHAR) * len);
+			GetEnvironmentVariable(L"HOME", dir, len);
+		}
+	}
 
 	/* set the console to ANSI/GUI codepage */
 	codepage = GetConsoleCP();
@@ -238,7 +255,7 @@ int main(void)
 				TRUE, /* handles inheritable? */
 				CREATE_UNICODE_ENVIRONMENT,
 				NULL, /* environment: use parent */
-				NULL, /* starting directory: use parent */
+				dir, /* starting directory: use parent */
 				&si, &pi);
 		if (br) {
 			if (wait)