read_key: drop optimization where we read 3 bytes at once

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

diff --git a/include/libbb.h b/include/libbb.h
index 788140d..963e2af 100644 (file)
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -933,54 +933,6 @@ void bb_displayroutes(int noresolve, int netstatfmt) FAST_FUNC;
 #endif
 
 
-/* "Keycodes" that report an escape sequence.
- * We use something which fits into signed char,
- * yet doesn't represent any valid Unicode characher.
- * Also, -1 is reserved for error indication and we don't use it. */
-enum {
-       KEYCODE_UP       =  -2,
-       KEYCODE_DOWN     =  -3,
-       KEYCODE_RIGHT    =  -4,
-       KEYCODE_LEFT     =  -5,
-       KEYCODE_HOME     =  -6,
-       KEYCODE_END      =  -7,
-       KEYCODE_INSERT   =  -8,
-       KEYCODE_DELETE   =  -9,
-       KEYCODE_PAGEUP   = -10,
-       KEYCODE_PAGEDOWN = -11,
-#if 0
-       KEYCODE_FUN1     = -12,
-       KEYCODE_FUN2     = -13,
-       KEYCODE_FUN3     = -14,
-       KEYCODE_FUN4     = -15,
-       KEYCODE_FUN5     = -16,
-       KEYCODE_FUN6     = -17,
-       KEYCODE_FUN7     = -18,
-       KEYCODE_FUN8     = -19,
-       KEYCODE_FUN9     = -20,
-       KEYCODE_FUN10    = -21,
-       KEYCODE_FUN11    = -22,
-       KEYCODE_FUN12    = -23,
-#endif
-       KEYCODE_CURSOR_POS = -0x100,
-       /* How long is the longest ESC sequence we know?
-        * We want it big enough to be able to contain
-        * cursor position sequence "ESC [ 9999 ; 9999 R"
-        */
-       KEYCODE_BUFFER_SIZE = 16
-};
-/* Note: fd may be in blocking or non-blocking mode, both make sense.
- * For one, less uses non-blocking mode.
- * Only the first read syscall inside read_key may block indefinitely
- * (unless fd is in non-blocking mode),
- * subsequent reads will time out after a few milliseconds.
- * Return of -1 means EOF or error (errno == 0 on EOF).
- * buffer[0] is used as a counter of buffered chars and must be 0
- * on first call.
- */
-int64_t read_key(int fd, char *buffer) FAST_FUNC;
-
-
 /* Networking */
 int create_icmp_socket(void) FAST_FUNC;
 int create_icmp6_socket(void) FAST_FUNC;
@@ -1209,6 +1161,54 @@ unsigned long long bb_makedev(unsigned int major, unsigned int minor) FAST_FUNC;
 #endif
 
 
+/* "Keycodes" that report an escape sequence.
+ * We use something which fits into signed char,
+ * yet doesn't represent any valid Unicode characher.
+ * Also, -1 is reserved for error indication and we don't use it. */
+enum {
+       KEYCODE_UP       =  -2,
+       KEYCODE_DOWN     =  -3,
+       KEYCODE_RIGHT    =  -4,
+       KEYCODE_LEFT     =  -5,
+       KEYCODE_HOME     =  -6,
+       KEYCODE_END      =  -7,
+       KEYCODE_INSERT   =  -8,
+       KEYCODE_DELETE   =  -9,
+       KEYCODE_PAGEUP   = -10,
+       KEYCODE_PAGEDOWN = -11,
+#if 0
+       KEYCODE_FUN1     = -12,
+       KEYCODE_FUN2     = -13,
+       KEYCODE_FUN3     = -14,
+       KEYCODE_FUN4     = -15,
+       KEYCODE_FUN5     = -16,
+       KEYCODE_FUN6     = -17,
+       KEYCODE_FUN7     = -18,
+       KEYCODE_FUN8     = -19,
+       KEYCODE_FUN9     = -20,
+       KEYCODE_FUN10    = -21,
+       KEYCODE_FUN11    = -22,
+       KEYCODE_FUN12    = -23,
+#endif
+       KEYCODE_CURSOR_POS = -0x100,
+       /* How long is the longest ESC sequence we know?
+        * We want it big enough to be able to contain
+        * cursor position sequence "ESC [ 9999 ; 9999 R"
+        */
+       KEYCODE_BUFFER_SIZE = 16
+};
+/* Note: fd may be in blocking or non-blocking mode, both make sense.
+ * For one, less uses non-blocking mode.
+ * Only the first read syscall inside read_key may block indefinitely
+ * (unless fd is in non-blocking mode),
+ * subsequent reads will time out after a few milliseconds.
+ * Return of -1 means EOF or error (errno == 0 on EOF).
+ * buffer[0] is used as a counter of buffered chars and must be 0
+ * on first call.
+ */
+int64_t read_key(int fd, char *buffer) FAST_FUNC;
+
+
 #if ENABLE_FEATURE_EDITING
 /* It's NOT just ENABLEd or disabled. It's a number: */
 # ifdef CONFIG_FEATURE_EDITING_HISTORY

diff --git a/libbb/lineedit.c b/libbb/lineedit.c
index a0b1bcf..81f6fde 100644 (file)
--- a/libbb/lineedit.c
+++ b/libbb/lineedit.c
@@ -1451,10 +1451,13 @@ static int lineedit_read_key(char *read_key_buffer)
        pfd.events = POLLIN;
        do {
  poll_again:
-               /* Wait for input. Can't just call read_key, it will return
-                * at once if stdin is in non-blocking mode. */
-               safe_poll(&pfd, 1, -1);
-               /* note: read_key sets errno to 0 on success: */
+               if (read_key_buffer[0] == 0) {
+                       /* Wait for input. Can't just call read_key,
+                        * it returns at once if stdin
+                        * is in non-blocking mode. */
+                       safe_poll(&pfd, 1, -1);
+               }
+               /* Note: read_key sets errno to 0 on success: */
                ic = read_key(STDIN_FILENO, read_key_buffer);
                if (ENABLE_FEATURE_EDITING_ASK_TERMINAL
                 && (int32_t)ic == KEYCODE_CURSOR_POS

diff --git a/libbb/read_key.c b/libbb/read_key.c
index 3771045..6f6c39e 100644 (file)
--- a/libbb/read_key.c
+++ b/libbb/read_key.c
@@ -69,11 +69,14 @@ int64_t FAST_FUNC read_key(int fd, char *buffer)
        errno = 0;
        n = (unsigned char) *buffer++;
        if (n == 0) {
-               /* If no data, block waiting for input. If we read more
-                * than the minimal ESC sequence size, the "n=0" below
-                * would instead have to figure out how much to keep,
-                * resulting in larger code. */
-               n = safe_read(fd, buffer, 3);
+               /* If no data, block waiting for input.
+                * It is tempting to read more than one byte here,
+                * but it breaks pasting. Example: at shell prompt,
+                * user presses "c","a","t" and then pastes "\nline\n".
+                * When we were reading 3 bytes here, we were eating
+                * "li" too, and cat was getting wrong input.
+                */
+               n = safe_read(fd, buffer, 1);
                if (n <= 0)
                        return -1;
        }

diff --git a/shell/hush.c b/shell/hush.c
index add40eb..5fa693b 100644 (file)
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -1006,7 +1006,7 @@ static void restore_G_args(save_arg_t *sv, char **argv)
  * Commands run in command substitution ("`cmd`")
  * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
  *
- * Ordinary commands have signals set to SIG_IGN/DFL set as inherited
+ * Ordinary commands have signals set to SIG_IGN/DFL as inherited
  * by the shell from its parent.
  *
  * Siganls which differ from SIG_DFL action
@@ -1285,7 +1285,7 @@ static int set_local_var(char *str, int flg_export, int flg_read_only)
                if (strncmp(cur->varstr, str, name_len) != 0) {
                        if (!cur->next) {
                                /* Bail out. Note that now cur points
-                                * to last var in linked list */
+                                * to the last var in the linked list */
                                break;
                        }
                        cur = cur->next;