Returning a shared buffer invites very subtle bugs due to reentrancy or
multi-threading, as demonstrated by the previous patch.
There was an unfinished effort to abolish this [1].
Let's finally rid of `real_path()`, using `strbuf_realpath()` instead.
This patch uses a local `strbuf` for most places where `real_path()` was
previously called.
However, two places return the value of `real_path()` to the caller. For
them, a `static` local `strbuf` was added, effectively pushing the
problem one level higher:
    read_gitfile_gently()
    get_superproject_working_tree()
[1] https://lore.kernel.org/git/1480964316-99305-1-git-send-email-bmwill@google.com/
Signed-off-by: Alexandr Miloslavskiy <alexandr.miloslavskiy@syntevo.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
		
	
		
			
				
	
	
		
			129 lines
		
	
	
		
			3.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			129 lines
		
	
	
		
			3.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
#include "cache.h"
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#include "config.h"
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#include "strbuf.h"
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#include "run-command.h"
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#include "sigchain.h"
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#ifndef DEFAULT_EDITOR
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#define DEFAULT_EDITOR "vi"
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#endif
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int is_terminal_dumb(void)
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{
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	const char *terminal = getenv("TERM");
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	return !terminal || !strcmp(terminal, "dumb");
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}
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const char *git_editor(void)
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{
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	const char *editor = getenv("GIT_EDITOR");
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	int terminal_is_dumb = is_terminal_dumb();
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	if (!editor && editor_program)
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		editor = editor_program;
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	if (!editor && !terminal_is_dumb)
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		editor = getenv("VISUAL");
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	if (!editor)
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		editor = getenv("EDITOR");
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	if (!editor && terminal_is_dumb)
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		return NULL;
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	if (!editor)
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		editor = DEFAULT_EDITOR;
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	return editor;
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}
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const char *git_sequence_editor(void)
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{
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	const char *editor = getenv("GIT_SEQUENCE_EDITOR");
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	if (!editor)
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		git_config_get_string_const("sequence.editor", &editor);
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	if (!editor)
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		editor = git_editor();
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	return editor;
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}
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static int launch_specified_editor(const char *editor, const char *path,
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				   struct strbuf *buffer, const char *const *env)
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{
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	if (!editor)
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		return error("Terminal is dumb, but EDITOR unset");
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	if (strcmp(editor, ":")) {
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		struct strbuf realpath = STRBUF_INIT;
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		const char *args[] = { editor, NULL, NULL };
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		struct child_process p = CHILD_PROCESS_INIT;
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		int ret, sig;
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		int print_waiting_for_editor = advice_waiting_for_editor && isatty(2);
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		if (print_waiting_for_editor) {
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			/*
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			 * A dumb terminal cannot erase the line later on. Add a
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			 * newline to separate the hint from subsequent output.
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			 *
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			 * Make sure that our message is separated with a whitespace
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			 * from further cruft that may be written by the editor.
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			 */
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			const char term = is_terminal_dumb() ? '\n' : ' ';
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			fprintf(stderr,
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				_("hint: Waiting for your editor to close the file...%c"),
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				term);
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			fflush(stderr);
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		}
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		strbuf_realpath(&realpath, path, 1);
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		args[1] = realpath.buf;
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		p.argv = args;
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		p.env = env;
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		p.use_shell = 1;
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		p.trace2_child_class = "editor";
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		if (start_command(&p) < 0) {
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			strbuf_release(&realpath);
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			return error("unable to start editor '%s'", editor);
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		}
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		sigchain_push(SIGINT, SIG_IGN);
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		sigchain_push(SIGQUIT, SIG_IGN);
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		ret = finish_command(&p);
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		strbuf_release(&realpath);
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		sig = ret - 128;
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		sigchain_pop(SIGINT);
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		sigchain_pop(SIGQUIT);
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		if (sig == SIGINT || sig == SIGQUIT)
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			raise(sig);
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		if (ret)
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			return error("There was a problem with the editor '%s'.",
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					editor);
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		if (print_waiting_for_editor && !is_terminal_dumb())
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			/*
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			 * Erase the entire line to avoid wasting the
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			 * vertical space.
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			 */
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			term_clear_line();
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	}
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	if (!buffer)
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		return 0;
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	if (strbuf_read_file(buffer, path, 0) < 0)
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		return error_errno("could not read file '%s'", path);
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	return 0;
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}
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int launch_editor(const char *path, struct strbuf *buffer, const char *const *env)
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{
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	return launch_specified_editor(git_editor(), path, buffer, env);
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}
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int launch_sequence_editor(const char *path, struct strbuf *buffer,
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			   const char *const *env)
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{
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	return launch_specified_editor(git_sequence_editor(), path, buffer, env);
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}
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