implement save_hist=always

- create setting group for history
- add save_hist=always
- save history on quit only when save_hist=quit
- update history in pushHashHist when save_hist=always

We adjust the number of history based on the size of history saved in
the previous update. In this way we don't need to store history in local
memory, but the size of history may differ from the size limit.

history.c

@@ -54,6 +54,46 @@ loadHistory(Hist *hist)
     fclose(f);
 }
 
+void
+saveOneHistory(const char *ptr)
+{
+    FILE *f;
+    Str line;
+    long ri, wi;
+    static int prev_num_hist = 0;
+    int num_skip = prev_num_hist - URLHistSize;
+
+    if ((f = fopen(rcFile(HISTORY_FILE), "r+t")) == NULL)
+        return;
+
+    ri = wi = 0;
+    prev_num_hist = 1;
+    flock(fileno(f), LOCK_EX);
+    while (!feof(f)) {
+	line = Strfgets(f);
+	Strchop(line);
+	Strremovefirstspaces(line);
+	Strremovetrailingspaces(line);
+	if (line->length == 0)
+	    continue;
+	if (num_skip-- > 0)
+	    continue;
+	if (!Strcmp_charp(line, ptr))
+	    continue;
+	prev_num_hist++;
+
+	ri = ftell(f);
+	fseek(f, wi, SEEK_SET);
+	fprintf(f, "%s\n", (char *)line->ptr);
+	wi = ftell(f);
+	fseek(f, ri, SEEK_SET);
+    }
+    fseek(f, wi, SEEK_SET);
+    fprintf(f, "%s\n", ptr);
+    ftruncate(fileno(f), ftell(f));
+    fclose(f);
+}
+
 void
 saveHistory(Hist *hist, size_t size)
 {
@@ -150,6 +190,11 @@ pushHist(Hist *hist, char *ptr)
 HistItem *
 pushHashHist(Hist *hist, char *ptr)
 {
+#ifdef USE_HISTORY
+    if (UseHistory && SaveURLHist == WHEN_SAVE_HIST_ALWAYS)
+	saveOneHistory(ptr);
+#endif /* USE_HISTORY */
+
     HistItem *item;
 
     if (hist == NULL || hist->list == NULL)

history.h

@@ -7,6 +7,10 @@
 
 #define HIST_HASH_SIZE 127
 
+#define WHEN_SAVE_HIST_NEVER  0
+#define WHEN_SAVE_HIST_QUIT   1
+#define WHEN_SAVE_HIST_ALWAYS 2
+
 typedef ListItem HistItem;
 
 typedef GeneralList HistList;

main.c

@@ -2419,7 +2419,7 @@ _quitfm(int confirm)
     save_cookies();
 #endif				/* USE_COOKIE */
 #ifdef USE_HISTORY
-    if (UseHistory && SaveURLHist)
+    if (UseHistory && SaveURLHist == WHEN_SAVE_HIST_QUIT)
 	saveHistory(URLHist, URLHistSize);
 #endif				/* USE_HISTORY */
     w3m_exit(0);

rc.c

@@ -331,6 +331,15 @@ static struct sel_c auto_detect_str[] = {
 };
 #endif
 
+#ifdef USE_HISTORY
+static struct sel_c when_save_hist[] = {
+    {N_S(WHEN_SAVE_HIST_NEVER), N_("never")},
+    {N_S(WHEN_SAVE_HIST_QUIT), N_("quit")},
+    {N_S(WHEN_SAVE_HIST_ALWAYS), N_("always")},
+    {0, NULL, NULL}
+};
+#endif
+
 struct param_ptr params1[] = {
     {"tabstop", P_NZINT, PI_TEXT, (void *)&Tabstop, CMT_TABSTOP, NULL},
     {"indent_incr", P_NZINT, PI_TEXT, (void *)&IndentIncr, CMT_INDENT_INCR,
@@ -432,13 +441,18 @@ struct param_ptr params2[] = {
 #endif				/* USE_COLOR */
 
 
-struct param_ptr params3[] = {
-    {"pagerline", P_NZINT, PI_TEXT, (void *)&PagerMax, CMT_PAGERLINE, NULL},
 #ifdef USE_HISTORY
+struct param_ptr params11[] = {
     {"use_history", P_INT, PI_ONOFF, (void *)&UseHistory, CMT_HISTORY, NULL},
     {"history", P_INT, PI_TEXT, (void *)&URLHistSize, CMT_HISTSIZE, NULL},
-    {"save_hist", P_INT, PI_ONOFF, (void *)&SaveURLHist, CMT_SAVEHIST, NULL},
+    {"save_hist", P_INT, PI_SEL_C, (void *)&SaveURLHist, CMT_SAVEHIST,
+     (void *)when_save_hist},
+};
 #endif				/* USE_HISTORY */
+
+
+struct param_ptr params3[] = {
+    {"pagerline", P_NZINT, PI_TEXT, (void *)&PagerMax, CMT_PAGERLINE, NULL},
     {"confirm_qq", P_INT, PI_ONOFF, (void *)&confirm_on_quit, CMT_CONFIRM_QQ,
      NULL},
     {"close_tab_back", P_INT, PI_ONOFF, (void *)&close_tab_back,
@@ -683,6 +697,7 @@ struct param_section sections[] = {
 #ifdef USE_COLOR
     {N_("Color Settings"), params2},
 #endif				/* USE_COLOR */
+    {N_("History Settings"), params11},
     {N_("Miscellaneous Settings"), params3},
     {N_("Directory Settings"), params5},
     {N_("External Program Settings"), params6},