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4074d4955

Denys Vlasenko

2016-09-30

SUCCESS Duration: 242s

Subject

hush: fix interactive input handling of backslash+newline

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Architecture & Compiler Flags

Architecture: x86_64-linux-gnu Compiler: gcc (Ubuntu 11.4.0-1ubuntu1~22.04.3) 11.4.0

—

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(log yok)

Commit Diff GitHub →

shell/hush.c +89 -74

shell/hush.c+89 -74

@@ -470,11 +470,9 @@ typedef struct in_str {
	FILE *file;
	int (get) (struct in_str ) FAST_FUNC;
	int (peek) (struct in_str ) FAST_FUNC;
-	int (peek2) (struct in_str ) FAST_FUNC;
	} in_str;
	#define i_getch(input) ((input)->get(input))
	#define i_peek(input) ((input)->peek(input))
-	#define i_peek2(input) ((input)->peek2(input))

	/* The descrip member of this structure is only used to make
	* debugging output pretty */
@@ -2129,6 +2127,14 @@ static void reinit_unicode_for_hush(void)
	*/

	#if ENABLE_HUSH_INTERACTIVE
+	/* To test correct lineedit/interactive behavior, type from command line:
+	* echo $P\
+	* \
+	* AT\
+	* H\
+	* \
+	* It excercises a lot of corner cases.
+	*/
	static void cmdedit_update_prompt(void)
	{
	if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
@@ -2159,7 +2165,7 @@ static const char *setup_prompt_string(int promptmode)
	prompt_str = G.PS2;
	} else
	prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
-	debug_printf("result '%s'\n", prompt_str);
+	debug_printf("prompt_str '%s'\n", prompt_str);
	return prompt_str;
	}
	static int get_user_input(struct in_str *i)
@@ -2169,8 +2175,6 @@ static int get_user_input(struct in_str *i)

	prompt_str = setup_prompt_string(i->promptmode);
	# if ENABLE_FEATURE_EDITING
-	/* Enable command line editing only while a command line
-	* is actually being read */
	do {
	reinit_unicode_for_hush();
	G.flag_SIGINT = 0;
@@ -2183,13 +2187,13 @@ static int get_user_input(struct in_str *i)
	/* catch SIGINT etc (^C is handled by read_line_input) */
	check_and_run_traps();
	} while (r == 0 \|\| G.flag_SIGINT); /* repeat if ^C or SIGINT */
-	i->p = G.user_input_buf;
	if (r < 0) {
	/* EOF/error detected */
-	G.user_input_buf[0] = '\0';
-	i->peek_buf[1] = i->peek_buf[0] = r = EOF;
+	i->p = NULL;
+	i->peek_buf[0] = r = EOF;
	return r;
	}
+	i->p = G.user_input_buf;
	return (unsigned char)*i->p++;
	# else
	do {
@@ -2209,18 +2213,45 @@ static int get_user_input(struct in_str *i)
	return r;
	# endif
	}
-	#endif /* INTERACTIVE */
-
	/* This is the magic location that prints prompts
	* and gets data back from the user */
+	static int fgetc_interactive(struct in_str *i)
+	{
+	int ch;
+	/* If it's interactive stdin, get new line. */
+	if (G_interactive_fd && i->file == stdin) {
+	/* Returns first char (or EOF), the rest is in i->p[] */
+	ch = get_user_input(i);
+	i->promptmode = 1; /* PS2 */
+	} else {
+	/* Not stdin: script file, sourced file, etc */
+	do ch = fgetc(i->file); while (ch == '\0');
+	}
+	return ch;
+	}
+	#else
+	static inline int fgetc_interactive(struct in_str *i)
+	{
+	int ch;
+	do ch = fgetc(i->file); while (ch == '\0');
+	return ch;
+	}
+	#endif /* INTERACTIVE */
+
	static int FAST_FUNC file_get(struct in_str *i)
	{
	int ch;

-	/* If there is data waiting, eat it up */
+	#if ENABLE_FEATURE_EDITING
+	/* This can be stdin, check line editing char[] buffer */
+	if (i->p && *i->p != '\0') {
+	ch = (unsigned char)*i->p++;
+	goto out;
+	}
+	#endif
	/* peek_buf[] is an int array, not char. Can contain EOF. */
	ch = i->peek_buf[0];
-	if (ch != '\0') {
+	if (ch != 0) {
	int ch2 = i->peek_buf[1];
	i->peek_buf[0] = ch2;
	if (ch2 == 0) /* very likely, avoid redundant write */
@@ -2229,86 +2260,46 @@ static int FAST_FUNC file_get(struct in_str *i)
	goto out;
	}

-	#if ENABLE_HUSH_INTERACTIVE
-	/* This can be stdin, check line editing char[] buffer */
-	if (i->p && *i->p != '\0') {
-	ch = (unsigned char)*i->p++;
-	goto out;
-	}
-	/* It's empty.
-	* If it's interactive stdin, get new line.
-	*/
-	if (G_interactive_fd && i->file == stdin) {
-	/* Returns first char (or EOF), the rest are in i->p[] */
-	ch = get_user_input(i);
-	i->promptmode = 1; /* PS2 */
-	goto out;
-	}
-	/* Not stdin: script file */
-	#endif
-	do ch = fgetc(i->file); while (ch == '\0');
+	ch = fgetc_interactive(i);
	out:
	debug_printf("file_get: got '%c' %d\n", ch, ch);
	i->last_char = ch;
	return ch;
	}

-	/* All callers guarantee this routine will never
-	* be used right after a newline, so prompting is not needed.
-	*/
	static int FAST_FUNC file_peek(struct in_str *i)
	{
	int ch;

-	/* peek_buf[] is an int array, not char. Can contain EOF. */
-	ch = i->peek_buf[0];
-	if (ch != '\0')
-	return ch;
-
-	#if ENABLE_HUSH_INTERACTIVE
+	#if ENABLE_FEATURE_EDITING && ENABLE_HUSH_INTERACTIVE
	/* This can be stdin, check line editing char[] buffer */
	if (i->p && *i->p != '\0')
	return (unsigned char)*i->p;
	#endif
+	/* peek_buf[] is an int array, not char. Can contain EOF. */
+	ch = i->peek_buf[0];
+	if (ch != 0)
+	return ch;

-	do ch = fgetc(i->file); while (ch == '\0');
-	i->peek_buf[0] = ch;
-	i->peek_buf[1] = 0;
+	/* Need to get a new char */
+	ch = fgetc_interactive(i);
	debug_printf("file_peek: got '%c' %d\n", ch, ch);
-	return ch;
-	}

-	/* Only ever called if i_peek() was called, and did not return EOF */
-	static int FAST_FUNC file_peek2(struct in_str *i)
-	{
-	int ch;
-
-	/* peek_buf[] is an int array, not char. Can contain EOF. */
-	ch = i->peek_buf[0];
-	if (ch != 0) {
-	/* peek_buf[] is not empty. Is there 2nd char? */
-	ch = i->peek_buf[1];
-	if (ch == 0) {
-	/* We did not read it yet, get it now */
-	do ch = fgetc(i->file); while (ch == '\0');
-	i->peek_buf[1] = ch;
-	}
-	goto out;
+	/* Save it by either rolling back line editing buffer, or in i->peek_buf[0] */
+	#if ENABLE_FEATURE_EDITING && ENABLE_HUSH_INTERACTIVE
+	if (i->p) {
+	i->p -= 1;
+	return ch;
	}
-
-	#if ENABLE_HUSH_INTERACTIVE
-	/* This can be stdin, check line editing char[] buffer */
-	if (i->p && i->p[0] != '\0')
-	ch = i->p[1];
	#endif
-	out:
-	debug_printf("file_peek2: got '%c' %d\n", ch, ch);
+	i->peek_buf[0] = ch;
+	/i->peek_buf[1] = 0; - already is /
	return ch;
	}

	static int FAST_FUNC static_get(struct in_str *i)
	{
-	int ch = *i->p;
+	int ch = (unsigned char)*i->p;
	if (ch != '\0') {
	i->p++;
	i->last_char = ch;
@@ -2320,13 +2311,39 @@ static int FAST_FUNC static_get(struct in_str *i)
	static int FAST_FUNC static_peek(struct in_str *i)
	{
	/* Doesn't report EOF on NUL. None of the callers care. */
-	return *i->p;
+	return (unsigned char)*i->p;
	}

-	/* Only ever called if i_peek() was called, and did not return EOF */
-	static int FAST_FUNC static_peek2(struct in_str *i)
+	/* Only ever called if i_peek() was called, and did not return EOF.
+	* IOW: we know the previous peek saw an ordinary char, not EOF, not NUL,
+	* not end-of-line. Therefore we never need to read a new editing line here.
+	*/
+	static int i_peek2(struct in_str *i)
	{
-	return i->p[1];
+	int ch;
+
+	/* There are two cases when i->p[] buffer exists.
+	* (1) it's a string in_str.
+	* (2) It's a file, and we have s saved line editing buffer.
+	* In both cases, we know that i->p[0] exists and not NUL, and
+	* the peek2 result is in i->p[1].
+	*/
+	if (i->p)
+	return (unsigned char)i->p[1];
+
+	/* Now we know it is a file-based in_str. */
+
+	/* peek_buf[] is an int array, not char. Can contain EOF. */
+	/* Is there 2nd char? */
+	ch = i->peek_buf[1];
+	if (ch == 0) {
+	/* We did not read it yet, get it now */
+	do ch = fgetc(i->file); while (ch == '\0');
+	i->peek_buf[1] = ch;
+	}
+
+	debug_printf("file_peek2: got '%c' %d\n", ch, ch);
+	return ch;
	}

	static void setup_file_in_str(struct in_str i, FILE f)
@@ -2334,7 +2351,6 @@ static void setup_file_in_str(struct in_str i, FILE f)
	memset(i, 0, sizeof(*i));
	i->get = file_get;
	i->peek = file_peek;
-	i->peek2 = file_peek2;
	/* i->promptmode = 0; - PS1 (memset did it) */
	i->file = f;
	/* i->p = NULL; */
@@ -2345,7 +2361,6 @@ static void setup_string_in_str(struct in_str i, const char s)
	memset(i, 0, sizeof(*i));
	i->get = static_get;
	i->peek = static_peek;
-	i->peek2 = static_peek2;
	/* i->promptmode = 0; - PS1 (memset did it) */
	i->p = s;
	}