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>

1 files changed, 25 insertions, 24 deletions

diff --git a/miscutils/conspy.c b/miscutils/conspy.c
index 7ba7959a2..ae471a3fa 100644
--- 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));