ash,hush: optional support for $HISTFILESIZE.

Based on patch from Alexey Fomenko (ext-alexey.fomenko AT nokia.com)

function                                             old     new   delta
size_from_HISTFILESIZE                                 -      44     +44
hush_main                                            998    1025     +27
ash_main                                            1348    1374     +26
read_line_input                                     3361    3372     +11
new_line_input_t                                      17      24      +7

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

2 files changed, 32 insertions, 17 deletions

diff --git a/libbb/Config.src b/libbb/Config.src
index a25af23b4..0ea8f43ab 100644
--- a/libbb/Config.src
+++ b/libbb/Config.src
@@ -80,11 +80,12 @@ config FEATURE_EDITING_VI
 
 config FEATURE_EDITING_HISTORY
         int "History size"
-        range 0 99999
+        # Don't allow way too big values here, code uses fixed "char *history[N]" struct member
+        range 0 9999
         default 255
         depends on FEATURE_EDITING
         help
-          Specify command history size.
+          Specify command history size (0 - disable).
 
 config FEATURE_EDITING_SAVEHISTORY
         bool "History saving"
diff --git a/libbb/lineedit.c b/libbb/lineedit.c
index b7a2b31dc..095ccfbef 100644
--- a/libbb/lineedit.c
+++ b/libbb/lineedit.c
@@ -1243,12 +1243,26 @@ line_input_t* FAST_FUNC new_line_input_t(int flags)
 {
         line_input_t *n = xzalloc(sizeof(*n));
         n->flags = flags;
+        n->max_history = MAX_HISTORY;
         return n;
 }
 
 
 #if MAX_HISTORY > 0
 
+unsigned size_from_HISTFILESIZE(const char *hp)
+{
+        int size = MAX_HISTORY;
+        if (hp) {
+                size = atoi(hp);
+                if (size <= 0)
+                        return 1;
+                if (size > MAX_HISTORY)
+                        return MAX_HISTORY;
+        }
+        return size;
+}
+
 static void save_command_ps_at_cur_history(void)
 {
         if (command_ps[0] != BB_NUL) {
@@ -1339,7 +1353,7 @@ static void load_history(line_input_t *st_parm)
                         temp_h[idx] = line;
                         st_parm->cnt_history_in_file++;
                         idx++;
-                        if (idx == MAX_HISTORY)
+                        if (idx == st_parm->max_history)
                                 idx = 0;
                 }
                 fclose(fp);
@@ -1348,18 +1362,18 @@ static void load_history(line_input_t *st_parm)
                 if (st_parm->cnt_history_in_file) {
                         while (temp_h[idx] == NULL) {
                                 idx++;
-                                if (idx == MAX_HISTORY)
+                                if (idx == st_parm->max_history)
                                         idx = 0;
                         }
                 }
 
                 /* copy temp_h[] to st_parm->history[] */
-                for (i = 0; i < MAX_HISTORY;) {
+                for (i = 0; i < st_parm->max_history;) {
                         line = temp_h[idx];
                         if (!line)
                                 break;
                         idx++;
-                        if (idx == MAX_HISTORY)
+                        if (idx == st_parm->max_history)
                                 idx = 0;
                         line_len = strlen(line);
                         if (line_len >= MAX_LINELEN)
@@ -1390,7 +1404,7 @@ static void save_history(char *str)
 
         /* did we write so much that history file needs trimming? */
         state->cnt_history_in_file++;
-        if (state->cnt_history_in_file > MAX_HISTORY * 4) {
+        if (state->cnt_history_in_file > state->max_history * 4) {
                 char *new_name;
                 line_input_t *st_temp;
 
@@ -1436,20 +1450,20 @@ static void remember_in_history(char *str)
         if (i && strcmp(state->history[i-1], str) == 0)
                 return;
 
-        free(state->history[MAX_HISTORY]); /* redundant, paranoia */
-        state->history[MAX_HISTORY] = NULL; /* redundant, paranoia */
+        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[MAX_HISTORY] empty, hence >=, not > */
-        if (i >= MAX_HISTORY) {
+        /* we need to keep history[state->max_history] empty, hence >=, not > */
+        if (i >= state->max_history) {
                 free(state->history[0]);
-                for (i = 0; i < MAX_HISTORY-1; i++)
+                for (i = 0; i < state->max_history-1; i++)
                         state->history[i] = state->history[i+1];
-                /* i == MAX_HISTORY-1 */
+                /* i == state->max_history-1 */
         }
-        /* i <= MAX_HISTORY-1 */
+        /* i <= state->max_history-1 */
         state->history[i++] = xstrdup(str);
-        /* i <= MAX_HISTORY */
+        /* i <= state->max_history */
         state->cur_history = i;
         state->cnt_history = i;
 # if MAX_HISTORY > 0 && ENABLE_FEATURE_EDITING_SAVEHISTORY
@@ -1970,7 +1984,7 @@ int FAST_FUNC read_line_input(line_input_t *st, const char *prompt, char *comman
                 maxsize = MAX_LINELEN;
         S.maxsize = maxsize;
 
-        /* With null flags, no other fields are ever used */
+        /* With zero flags, no other fields are ever used */
         state = st ? st : (line_input_t*) &const_int_0;
 #if MAX_HISTORY > 0
 # if ENABLE_FEATURE_EDITING_SAVEHISTORY
@@ -2022,7 +2036,7 @@ int FAST_FUNC read_line_input(line_input_t *st, const char *prompt, char *comman
 #endif
 
 #if 0
-        for (i = 0; i <= MAX_HISTORY; i++)
+        for (i = 0; i <= state->max_history; i++)
                 bb_error_msg("history[%d]:'%s'", i, state->history[i]);
         bb_error_msg("cur_history:%d cnt_history:%d", state->cur_history, state->cnt_history);
 #endif