fix errors in detecting non-modified areas

function                                             old     new   delta
screen_char                                          100     102      +2
cleanup                                               84      86      +2
screen_dump                                          215     210      -5
conspy_main                                         1503    1491     -12

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

diff --git a/miscutils/conspy.c b/miscutils/conspy.c
index 7ba7959a2d0e23d359d2b629a7edfe47fd1415be..ae471a3fa2c6913874e07cb9f9cf6b711baedb67 100644 (file)
--- a/miscutils/conspy.c
+++ b/miscutils/conspy.c
@@ -62,7 +62,6 @@ struct globals {
        int kbd_fd;
        unsigned width;
        unsigned height;
-       char mask;
        char last_attr;
        struct screen_info info;
        struct termios term_orig;
@@ -73,6 +72,17 @@ struct globals {
        SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
 } while (0)
 
+enum {
+       FLAG_v,  // view only
+       FLAG_c,  // create device if need
+       FLAG_s,  // session
+       FLAG_n,  // no colors
+       FLAG_d,  // dump screen
+       FLAG_f,  // follow cursor
+};
+#define FLAG(x) (1 << FLAG_##x)
+#define BW (option_mask32 & FLAG(n))
+
 static void screen_read_close(int fd, char *data)
 {
        unsigned i, j;
@@ -95,7 +105,7 @@ static void screen_read_close(int fd, char *data)
 
 static void screen_char(char *data)
 {
-       if (((G.last_attr - ATTR(data)) & G.mask) != 0) {
+       if (!BW && G.last_attr != ATTR(data)) {
                //                            BLGCRMOW
                static const char color[8] = "04261537";
 
@@ -123,29 +133,32 @@ static void gotoxy(int row, int line)
 
 static void screen_dump(char *data)
 {
-       int space, linefeed, line, row;
+       int linefeed_cnt;
+       int line, row;
        int linecnt = G.info.lines - G.y;
 
        data += 2 * G.y * G.info.rows;
-       for (linefeed = line = 0; line < linecnt && line < G.height; line++) {
-               for (space = row = 0; row < G.info.rows; row++, NEXT(data)) {
+       linefeed_cnt = 0;
+       for (line = 0; line < linecnt && line < G.height; line++) {
+               int space_cnt = 0;
+               for (row = 0; row < G.info.rows; row++, NEXT(data)) {
                        unsigned tty_row = row - G.x; // if will catch row < G.x too
 
                        if (tty_row >= G.width)
                                continue;
-                       space++;
-                       if (((G.last_attr - ATTR(data)) & G.mask) && CHAR(data) == ' ')
+                       space_cnt++;
+                       if (BW && (CHAR(data) | ' ') == ' ')
                                continue;
-                       while (linefeed != 0) {
+                       while (linefeed_cnt != 0) {
                                bb_putchar('\r');
                                bb_putchar('\n');
-                               linefeed--;
+                               linefeed_cnt--;
                        }
-                       while (--space)
+                       while (--space_cnt)
                                bb_putchar(' ');
                        screen_char(data);
                }
-               linefeed++;
+               linefeed_cnt++;
        }
 }
 
@@ -173,7 +186,7 @@ static void cleanup(int code)
                close(G.kbd_fd);
        }
        // Reset attributes
-       if (G.mask != 0)
+       if (!BW)
                printf("\033[0m");
        bb_putchar('\n');
        if (code > 1)
@@ -234,16 +247,6 @@ static NOINLINE void start_shell_in_child(const char* tty_name)
        }
 }
 
-enum {
-       FLAG_v,  // view only
-       FLAG_c,  // create device if need
-       FLAG_s,  // session
-       FLAG_n,  // no colors
-       FLAG_d,  // dump screen
-       FLAG_f,  // follow cursor
-};
-#define FLAG(x) (1 << FLAG_##x)
-
 int conspy_main(int argc UNUSED_PARAM, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int conspy_main(int argc UNUSED_PARAM, char **argv)
 {
@@ -284,8 +287,6 @@ int conspy_main(int argc UNUSED_PARAM, char **argv)
                sprintf(vcsa_name + sizeof("/dev/vcsa")-1, "%u", ttynum);
        }
        sprintf(tty_name, "%s%u", "/dev/tty", ttynum);
-       if (!(opts & FLAG(n)))
-               G.mask = 0xff;
        if (opts & FLAG(c)) {
                if ((opts & (FLAG(s)|FLAG(v))) != FLAG(v))
                        create_cdev_if_doesnt_exist(tty_name, makedev(4, ttynum));