less: make read error reporting actually visible

function                                             old     new   delta
m_status_print                                       252     275     +23
status_print                                         111     122     +11
read_lines                                           783     775      -8
.rodata                                           107141  107131     -10
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 2/2 up/down: 34/-18)             Total: 16 bytes

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

1 files changed, 19 insertions, 10 deletions

diff --git a/miscutils/less.c b/miscutils/less.c
index 12bb31537..d275fd3b3 100644
--- a/miscutils/less.c
+++ b/miscutils/less.c
@@ -529,7 +529,7 @@ static void read_lines(void)
                                 readpos = 0;
                                 read_size = G.eof_error_ok;
                                 if (G.eof_error_ok <= 0) {
-                                        read_size = 0; // -1 would be seen as UNIT_MAX, prevent
+                                        read_size = 0; // -1 would be seen as UINT_MAX, prevent
                                         if (G.eof_error_ok < 0 && errno == EAGAIN)
                                                 G.eof_error_ok = 1; // "neither EOF nor error"
                                         goto reached_eof;
@@ -637,10 +637,13 @@ static void read_lines(void)
         if (ndelay_set == 0) // stdin was not nonblocking, restore that
                 fcntl(STDIN_FILENO, F_SETFL, fdflags);
 
-        if (G.eof_error_ok < 0) // error?
-                print_statusline(bb_msg_read_error);
+        // Will not be seen (overwritten immediately)
+        //if (G.eof_error_ok < 0) { // error?
+        //      print_statusline(bb_msg_read_error);
+        //      bb_error_msg("G.eof_error_ok:%d", G.eof_error_ok); sleep(5);
+        //} else
 #if ENABLE_FEATURE_LESS_FLAGS
-        else if (G.eof_error_ok == 0) // EOF?
+        if (G.eof_error_ok == 0) // EOF?
                 num_lines = max_lineno;
 #endif
 
@@ -715,17 +718,17 @@ static void m_status_print(void)
         clear_line();
         printf(HIGHLIGHT"%s", filename);
         if (num_files > 1)
-                printf(" (file %i of %i)", current_file, num_files);
+                printf(" (file %d of %d)", current_file, num_files);
 
         first = safe_lineno(cur_fline);
         last = (option_mask32 & FLAG_S)
                         ? MIN(first + max_displayed_line, max_lineno)
                         : safe_lineno(cur_fline + max_displayed_line);
-        printf(" lines %i-%i", first, last);
+        printf(" lines %d-%d", first, last);
 
         update_num_lines();
         if (num_lines >= 0)
-                printf("/%i", num_lines);
+                printf("/%d", num_lines);
 
         if (at_end()) {
                 printf(" (END)");
@@ -733,8 +736,11 @@ static void m_status_print(void)
                         printf(" - next: %s", files[current_file]);
         } else if (num_lines > 0) {
                 percent = (100 * last + num_lines/2) / num_lines;
-                printf(" %i%%", percent <= 100 ? percent : 100);
+                printf(" %d%%", percent <= 100 ? percent : 100);
         }
+        if (G.eof_error_ok < 0)
+                // Reproducer: strace -oLOG -e fault=read:error=EIO:when=2 less FILE
+                printf(" %s", bb_msg_read_error);
         printf(NORMAL);
 }
 #endif
@@ -764,6 +770,9 @@ static void status_print(void)
         p = "(END)";
         if (!cur_fline)
                 p = filename;
+        if (G.eof_error_ok < 0)
+                // Reproducer: strace -oLOG -e fault=read:error=EIO:when=2 less FILE
+                p = bb_msg_read_error;
         if (num_files > 1) {
                 printf(HIGHLIGHT"%s (file %i of %i)"NORMAL,
                                 p, current_file, num_files);
@@ -1137,7 +1146,7 @@ static int64_t getch_nowait(void)
                         int r;
                         /* NB: SIGWINCH interrupts poll() */
                         r = poll(pfd + dont_poll_stdin, 2 - dont_poll_stdin, -1);
-                        if (/*r < 0 && errno == EINTR &&*/ winch_counter)
+                        if (/*r < 0 && errno == EINTR &&*/ winch_counter != 0)
                                 return '\\'; /* anything which has no defined function */
                         if (r) break;
                 }
@@ -1927,7 +1936,7 @@ int less_main(int argc, char **argv)
                 int64_t keypress;
 
 #if ENABLE_FEATURE_LESS_WINCH
-                while (WINCH_COUNTER) {
+                while (WINCH_COUNTER != 0) {
  again:
                         winch_counter--;
                         IF_FEATURE_LESS_ASK_TERMINAL(G.winsize_err =) get_terminal_width_height(kbd_fd, &width, &max_displayed_line);