1 files changed, 31 insertions, 17 deletions

diff --git a/shell/shell_common.c b/shell/shell_common.c
index 7fb5f8c58..657f0df8f 100644
--- a/shell/shell_common.c
+++ b/shell/shell_common.c
@@ -55,7 +55,7 @@ const char* FAST_FUNC
 shell_builtin_read(struct builtin_read_params *params)
 {
         struct pollfd pfd[1];
-#define fd (pfd[0].fd) /* -u FD */
+#define fd (pfd->fd) /* -u FD */
         unsigned err;
         unsigned end_ms; /* -t TIMEOUT */
         int nchars; /* -n NUM */
@@ -144,7 +144,7 @@ shell_builtin_read(struct builtin_read_params *params)
                  * bash seems to ignore -p PROMPT for this use case.
                  */
                 int r;
-                pfd[0].events = POLLIN;
+                pfd->events = POLLIN;
                 r = poll(pfd, 1, /*timeout:*/ 0);
                 /* Return 0 only if poll returns 1 ("one fd ready"), else return 1: */
                 return (const char *)(uintptr_t)(r <= 0);
@@ -209,8 +209,8 @@ shell_builtin_read(struct builtin_read_params *params)
                          * 32-bit unix time wrapped (year 2038+).
                          */
                         if (timeout <= 0) { /* already late? */
-                                retval = (const char *)(uintptr_t)1;
-                                goto ret;
+                                retval = (const char *)(uintptr_t)2;
+                                break;
                         }
                 }
 
@@ -219,15 +219,23 @@ shell_builtin_read(struct builtin_read_params *params)
                  * regardless of SA_RESTART-ness of that signal!
                  */
                 errno = 0;
-                pfd[0].events = POLLIN;
-//TODO race with a signal arriving just before the poll!
+                pfd->events = POLLIN;
+
 #if ENABLE_PLATFORM_MINGW32
-                /* Don't poll if timeout is -1, it hurts performance. */
+                /* Don't poll if timeout is -1, it hurts performance.  The
+                 * caution above about interrupts isn't relevant on Windows
+                 * where Ctrl-C causes an event, not a signal.
+                 */
                 if (timeout >= 0)
 #endif
-                if (poll(pfd, 1, timeout) <= 0) {
-                        /* timed out, or EINTR */
+                /* test bb_got_signal, then poll(), atomically wrt signals */
+                if (check_got_signal_and_poll(pfd, timeout) <= 0) {
+                        /* timed out, or some error */
                         err = errno;
+                        if (!err) { /* timed out */
+                                retval = (const char *)(uintptr_t)2;
+                                break;
+                        }
                         retval = (const char *)(uintptr_t)1;
                         goto ret;
                 }
@@ -238,15 +246,18 @@ shell_builtin_read(struct builtin_read_params *params)
                         key = windows_read_key(fd, NULL, timeout);
                         if (key == 0x03) {
                                 /* ^C pressed */
-                                retval = (const char *)(uintptr_t)2;
+                                retval = (const char *)(uintptr_t)3;
                                 goto ret;
                         }
-                        else if (key == -1 || (key == 0x1a && bufpos == 0)) {
-                                /* timeout or ^Z at start of buffer */
+                        else if (key == -1) {
+                                /* timeout */
+                                retval = (const char *)(uintptr_t)2;
+                                break;
+                        } else if (key == 0x1a && bufpos == 0) {
+                                /* ^Z at start of buffer */
                                 retval = (const char *)(uintptr_t)1;
-                                goto ret;
-                        }
-                        else if (key == '\b') {
+                                break;
+                        } else if (key == '\b') {
                                 if (bufpos > 0) {
                                         --bufpos;
                                         ++nchars;
@@ -278,7 +289,7 @@ shell_builtin_read(struct builtin_read_params *params)
                                  *   and exit BS context.
                                  * - CR LF not in BS context: replace CR with LF */
                                 buffer[--bufpos] = c;
-                                ++nchars;
+                                nchars += 1 + (backslash == 2);
                         }
                 } else if (backslash == 2) {
                         /* We saw BS CR ??, keep escaped CR, exit BS context,
@@ -298,6 +309,9 @@ shell_builtin_read(struct builtin_read_params *params)
                                 backslash = 0;
                                 if (c != '\n')
                                         goto put;
+#if ENABLE_PLATFORM_MINGW32
+                                ++nchars;
+#endif
                                 continue;
                         }
                         if (c == '\\') {
@@ -338,7 +352,7 @@ shell_builtin_read(struct builtin_read_params *params)
                 }
  put:
                 bufpos++;
-        } while (--nchars);
+        } while (IF_PLATFORM_MINGW32(backslash ||) --nchars);
 
         if (argv[0]) {
                 /* Remove trailing space $IFS chars */