1 files changed, 62 insertions, 50 deletions

diff --git a/libbb/lineedit.c b/libbb/lineedit.c
index 8e2b37853..c8a0f37fe 100644
--- a/libbb/lineedit.c
+++ b/libbb/lineedit.c
@@ -457,7 +457,7 @@ static void put_cur_glyph_and_inc_cursor(void)
                  * have automargin (IOW: it is moving cursor to next line
                  * by itself (which is wrong for VT-10x terminals)),
                  * this will break things: there will be one extra empty line */
-                puts("\r"); /* + implicit '\n' */
+                fputs("\r\n", stderr);
 #else
                 /* VT-10x terminals don't wrap cursor to next line when last char
                  * on the line is printed - cursor stays "over" this char.
@@ -1302,9 +1302,10 @@ static void showfiles(void)
                         );
                 }
                 if (ENABLE_UNICODE_SUPPORT)
-                        puts(printable_string(matches[n]));
+                        fputs(printable_string(matches[n]), stderr);
                 else
-                        puts(matches[n]);
+                        fputs(matches[n], stderr);
+                bb_putchar_stderr('\n');
         }
 }
 
@@ -1595,8 +1596,8 @@ unsigned FAST_FUNC size_from_HISTFILESIZE(const char *hp)
 # endif
         if (hp) {
                 size = atoi(hp);
-                if (size <= 0)
-                        return 1;
+                if (size < 0)
+                        return 0;
                 if (size > MAX_HISTORY)
                         return MAX_HISTORY;
         }
@@ -1690,18 +1691,21 @@ static void load_history(line_input_t *st_parm)
         /* NB: do not trash old history if file can't be opened */
 
         fp = fopen_for_read(st_parm->hist_file);
-        if (fp) {
-                /* clean up old history */
-                for (idx = st_parm->cnt_history; idx > 0;) {
-                        idx--;
-                        free(st_parm->history[idx]);
-                        st_parm->history[idx] = NULL;
-                }
+        if (!fp)
+                return;
+
+        /* clean up old history */
+        for (idx = st_parm->cnt_history; idx > 0;) {
+                idx--;
+                free(st_parm->history[idx]);
+                st_parm->history[idx] = NULL;
+        }
 
-                /* fill temp_h[], retaining only last MAX_HISTORY lines */
-                memset(temp_h, 0, sizeof(temp_h));
-                idx = 0;
-                st_parm->cnt_history_in_file = 0;
+        /* fill temp_h[], retaining only last max_history lines */
+        memset(temp_h, 0, sizeof(temp_h));
+        idx = 0;
+        st_parm->cnt_history_in_file = 0;
+        if (st_parm->max_history != 0) {
                 while ((line = xmalloc_fgetline(fp)) != NULL) {
                         if (line[0] == '\0') {
                                 free(line);
@@ -1714,34 +1718,34 @@ static void load_history(line_input_t *st_parm)
                         if (idx == st_parm->max_history)
                                 idx = 0;
                 }
-                fclose(fp);
-
-                /* find first non-NULL temp_h[], if any */
-                if (st_parm->cnt_history_in_file) {
-                        while (temp_h[idx] == NULL) {
-                                idx++;
-                                if (idx == st_parm->max_history)
-                                        idx = 0;
-                        }
-                }
+        }
+        fclose(fp);
 
-                /* copy temp_h[] to st_parm->history[] */
-                for (i = 0; i < st_parm->max_history;) {
-                        line = temp_h[idx];
-                        if (!line)
-                                break;
+        /* find first non-NULL temp_h[], if any */
+        if (st_parm->cnt_history_in_file != 0) {
+                while (temp_h[idx] == NULL) {
                         idx++;
                         if (idx == st_parm->max_history)
                                 idx = 0;
-                        line_len = strlen(line);
-                        if (line_len >= MAX_LINELEN)
-                                line[MAX_LINELEN-1] = '\0';
-                        st_parm->history[i++] = line;
                 }
-                st_parm->cnt_history = i;
-                if (ENABLE_FEATURE_EDITING_SAVE_ON_EXIT)
-                        st_parm->cnt_history_in_file = i;
         }
+
+        /* copy temp_h[] to st_parm->history[] */
+        for (i = 0; i < st_parm->max_history;) {
+                line = temp_h[idx];
+                if (!line)
+                        break;
+                idx++;
+                if (idx == st_parm->max_history)
+                        idx = 0;
+                line_len = strlen(line);
+                if (line_len >= MAX_LINELEN)
+                        line[MAX_LINELEN-1] = '\0';
+                st_parm->history[i++] = line;
+        }
+        st_parm->cnt_history = i;
+        if (ENABLE_FEATURE_EDITING_SAVE_ON_EXIT)
+                st_parm->cnt_history_in_file = i;
 }
 
 #  if ENABLE_FEATURE_EDITING_SAVE_ON_EXIT
@@ -1749,17 +1753,27 @@ void FAST_FUNC save_history(line_input_t *st)
 {
         FILE *fp;
 
-        if (!st || !st->hist_file)
+        /* bash compat: HISTFILE="" disables history saving */
+        if (!st || !st->hist_file || !state->hist_file[0])
                 return;
         if (st->cnt_history <= st->cnt_history_in_file)
-                return;
+                return; /* no new entries were added */
+        /* note: if st->max_history is 0, we do not abort: we truncate the history to 0 lines */
 
-        fp = fopen(st->hist_file, "a");
+        fp = fopen(st->hist_file, (st->max_history == 0 ? "w" : "a"));
         if (fp) {
                 int i, fd;
                 char *new_name;
                 line_input_t *st_temp;
 
+                /* max_history==0 needs special-casing in general code,
+                 * just handle it in a simpler way: */
+                if (st->max_history == 0) {
+                        /* fopen("w") already truncated it */
+                        fclose(fp);
+                        return;
+                }
+
                 for (i = st->cnt_history_in_file; i < st->cnt_history; i++)
                         fprintf(fp, "%s\n", st->history[i]);
                 fclose(fp);
@@ -1769,6 +1783,8 @@ void FAST_FUNC save_history(line_input_t *st)
                 st_temp = new_line_input_t(st->flags);
                 st_temp->hist_file = st->hist_file;
                 st_temp->max_history = st->max_history;
+                /* load no more than max_history last lines */
+                /* (in unlikely case that file disappeared, st_temp gets empty history) */
                 load_history(st_temp);
 
                 /* write out temp file and replace hist_file atomically */
@@ -1792,13 +1808,13 @@ static void save_history(char *str)
         int fd;
         int len, len2;
 
-        if (!state->hist_file)
+        /* bash compat: HISTFILE="" disables history saving */
+        if (!state->hist_file || !state->hist_file[0])
                 return;
 
         fd = open(state->hist_file, O_WRONLY | O_CREAT | O_APPEND, 0600);
         if (fd < 0)
                 return;
-        xlseek(fd, 0, SEEK_END); /* paranoia */
         len = strlen(str);
         str[len] = '\n'; /* we (try to) do atomic write */
         len2 = full_write(fd, str, len + 1);
@@ -1853,13 +1869,10 @@ static void remember_in_history(char *str)
         if (str[0] == '\0')
                 return;
         i = state->cnt_history;
-        /* Don't save dupes */
-        if (i && strcmp(state->history[i-1], str) == 0)
+        /* Don't save dups */
+        if (i != 0 && strcmp(state->history[i-1], str) == 0)
                 return;
 
-        free(state->history[state->max_history]); /* redundant, paranoia */
-        state->history[state->max_history] = NULL; /* redundant, paranoia */
-
         /* If history[] is full, remove the oldest command */
         /* we need to keep history[state->max_history] empty, hence >=, not > */
         if (i >= state->max_history) {
@@ -1872,7 +1885,7 @@ static void remember_in_history(char *str)
                         state->cnt_history_in_file--;
 # endif
         }
-        /* i <= state->max_history-1 */
+        /* i < state->max_history */
         state->history[i++] = xstrdup(str);
         /* i <= state->max_history */
         state->cur_history = i;
@@ -2388,7 +2401,6 @@ static int lineedit_read_key(char *read_key_buffer, int timeout)
                                 errno = EINTR;
                                 return -1;
                         }
-//FIXME: still races here with signals, but small window to poll() inside read_key
                         IF_FEATURE_EDITING_WINCH(S.ok_to_redraw = 1;)
                         /* errno = 0; - read_key does this itself */
                         ic = read_key(STDIN_FILENO, read_key_buffer, timeout);