lineedit: fix problems with empty commands in history

diff --git a/libbb/lineedit.c b/libbb/lineedit.c
index a68e5a3..c2c3ea9 100644 (file)
--- a/libbb/lineedit.c
+++ b/libbb/lineedit.c
@@ -956,24 +956,33 @@ static void input_tab(smallint *lastWasTab)
 
 #if MAX_HISTORY > 0
 
+static void save_command_ps_at_cur_history(void)
+{
+       if (command_ps[0] != '\0') {
+               int cur = state->cur_history;
+               free(state->history[cur]);
+               state->history[cur] = xstrdup(command_ps);
+       }
+}
+
 /* state->flags is already checked to be nonzero */
-static void get_previous_history(void)
+static int get_previous_history(void)
 {
-       if (command_ps[0] != '\0' || state->history[state->cur_history] == NULL) {
-               free(state->history[state->cur_history]);
-               state->history[state->cur_history] = xstrdup(command_ps);
+       if ((state->flags & DO_HISTORY) && state->cur_history) {
+               save_command_ps_at_cur_history();
+               state->cur_history--;
+               return 1;
        }
-       state->cur_history--;
+       beep();
+       return 0;
 }
 
 static int get_next_history(void)
 {
        if (state->flags & DO_HISTORY) {
-               int ch = state->cur_history;
-               if (ch < state->cnt_history) {
-                       get_previous_history(); /* save the current history line */
-                       state->cur_history = ch + 1;
-                       return state->cur_history;
+               if (state->cur_history < state->cnt_history) {
+                       save_command_ps_at_cur_history(); /* save the current history line */
+                       return ++state->cur_history;
                }
        }
        beep();
@@ -995,6 +1004,7 @@ static void load_history(const char *fromfile)
                for (hi = state->cnt_history; hi > 0;) {
                        hi--;
                        free(state->history[hi]);
+                       state->history[hi] = NULL;
                }
 
                for (hi = 0; hi < MAX_HISTORY;) {
@@ -1006,14 +1016,14 @@ static void load_history(const char *fromfile)
                        l = strlen(hl);
                        if (l >= MAX_LINELEN)
                                hl[MAX_LINELEN-1] = '\0';
-                       if (l == 0 || hl[0] == ' ') {
+                       if (l == 0) {
                                free(hl);
                                continue;
                        }
                        state->history[hi++] = hl;
                }
                fclose(fp);
-               state->cur_history = state->cnt_history = hi;
+               state->cnt_history = hi;
        }
 }
 
@@ -1043,19 +1053,27 @@ static void remember_in_history(const char *str)
 
        if (!(state->flags & DO_HISTORY))
                return;
-
+       if (str[0] == '\0')
+               return;
        i = state->cnt_history;
-       free(state->history[MAX_HISTORY]);
-       state->history[MAX_HISTORY] = NULL;
-       /* After max history, remove the oldest command */
+       /* Don't save dupes */
+       if (i && strcmp(state->history[i-1], str) == 0)
+               return;
+
+       free(state->history[MAX_HISTORY]); /* redundant, paranoia */
+       state->history[MAX_HISTORY] = NULL; /* redundant, paranoia */
+
+       /* If history[] is full, remove the oldest command */
+       /* we need to keep history[MAX_HISTORY] empty, hence >=, not > */
        if (i >= MAX_HISTORY) {
                free(state->history[0]);
                for (i = 0; i < MAX_HISTORY-1; i++)
                        state->history[i] = state->history[i+1];
+               /* i == MAX_HISTORY-1 */
        }
-// Maybe "if (!i || strcmp(history[i-1], command) != 0) ..."
-// (i.e. do not save dups?)
+       /* i <= MAX_HISTORY-1 */
        state->history[i++] = xstrdup(str);
+       /* i <= MAX_HISTORY */
        state->cur_history = i;
        state->cnt_history = i;
 #if ENABLE_FEATURE_EDITING_SAVEHISTORY
@@ -1397,6 +1415,7 @@ int FAST_FUNC read_line_input(const char *prompt, char *command, int maxsize, li
        if ((state->flags & SAVE_HISTORY) && state->hist_file)
                load_history(state->hist_file);
 #endif
+       state->cur_history = state->cnt_history;
 
        /* prepare before init handlers */
        cmdedit_y = 0;  /* quasireal y, not true if line > xt*yt */
@@ -1432,6 +1451,13 @@ int FAST_FUNC read_line_input(const char *prompt, char *command, int maxsize, li
                }
        }
 #endif
+
+#if 0
+       for (ic = 0; ic <= MAX_HISTORY; ic++)
+               bb_error_msg("history[%d]:'%s'", ic, state->history[ic]);
+       bb_error_msg("cur_history:%d cnt_history:%d", state->cur_history, state->cnt_history);
+#endif
+
        /* Print out the command prompt */
        parse_and_put_prompt(prompt);
 
@@ -1540,11 +1566,8 @@ int FAST_FUNC read_line_input(const char *prompt, char *command, int maxsize, li
                vi_case(CTRL('P')|vbit:)
                vi_case('k'|vbit:)
                        /* Control-p -- Get previous command from history */
-                       if ((state->flags & DO_HISTORY) && state->cur_history > 0) {
-                               get_previous_history();
+                       if (get_previous_history())
                                goto rewrite_line;
-                       }
-                       beep();
                        break;
 #endif
 
@@ -1733,10 +1756,8 @@ int FAST_FUNC read_line_input(const char *prompt, char *command, int maxsize, li
 #if MAX_HISTORY > 0
                        case 'A':
                                /* Up Arrow -- Get previous command from history */
-                               if ((state->flags & DO_HISTORY) && state->cur_history > 0) {
-                                       get_previous_history();
+                               if (get_previous_history())
                                        goto rewrite_line;
-                               }
                                beep();
                                break;
                        case 'B':
@@ -1746,7 +1767,7 @@ int FAST_FUNC read_line_input(const char *prompt, char *command, int maxsize, li
  rewrite_line:
                                /* Rewrite the line with the selected history item */
                                /* change command */
-                               command_len = strlen(strcpy(command, state->history[state->cur_history]));
+                               command_len = strlen(strcpy(command, state->history[state->cur_history] ? : ""));
                                /* redraw and go to eol (bol, in vi */
                                redraw(cmdedit_y, (state->flags & VI_MODE) ? 9999 : 0);
                                break;