linenoise: submit and stay in history.

* linenoise/linenoise.c (struct lino_state): New member
save_hist_idx.
(edit): If save_hist_idx is set, jump to that history position
and clear it.  Handle ENTER in extended (Ctrl-X) mode
similarly to regular ENTER, but setting save_hist_idx.

* txr.1: Documented.

2 files changed, 33 insertions, 0 deletions

diff --git a/linenoise/linenoise.c b/linenoise/linenoise.c
index 93f4bf6c..1dd7577d 100644
--- a/linenoise/linenoise.c
+++ b/linenoise/linenoise.c
@@ -89,6 +89,7 @@ struct lino_state {
     char *clip;         /* Selection */
     int ifd;            /* Terminal stdin file descriptor. */
     int ofd;            /* Terminal stdout file descriptor. */
+    int save_hist_idx;  /* Jump to history position on entry into edit */
 
     /* Volatile state pertaining to just one linenoise call */
     char buf[LINENOISE_MAX_DISP];       /* Displayed line bufer. */
@@ -1676,6 +1677,16 @@ static int edit(lino_t *l, const char *prompt)
         l->error = lino_ioerr;
         return ret;
     }
+
+    if (l->save_hist_idx) {
+        int hi = l->history_len - l->save_hist_idx - 1;
+        l->history_index = l->save_hist_idx;
+        l->save_hist_idx = 0;
+        strcpy(l->data, l->history[hi]);
+        l->dpos = l->dlen = strlen(l->data);
+        l->need_refresh = 1;
+    }
+
     while(1) {
         unsigned char byte;
         int c;
@@ -1814,6 +1825,14 @@ static int edit(lino_t *l, const char *prompt)
                     clear_sel(l);
                 }
                 break;
+            case ENTER:
+                if (l->mlmode)
+                    edit_move_end(l);
+                if (l->need_refresh)
+                    refresh_line(l);
+                ret = l->len;
+                l->save_hist_idx = l->history_index;
+                goto out;
             default:
                 if (isdigit((unsigned char) c)) {
                     if (extend_num < 0)
diff --git a/txr.1 b/txr.1
index bff5c833..9cf5c862 100644
--- a/txr.1
+++ b/txr.1
@@ -38256,6 +38256,20 @@ Navigating to a history line manually using the up and down arrow keys (or
 Ctrl-P/Ctrl-N) has the same net effect same as locating that line using
 Ctrl-R search.
 
+.NP* Submit and Stay in History
+
+Normally when the Enter key is used on a recalled history line,
+the next time the listener is re-entered, it jumps back to the
+newest history position where a new line is about to be composed.
+
+The alternative command sequence Ctrl-X, Enter provides a useful alternative
+behavior. After the submitted line is processed, the listener doesn't jump to
+the newest history position. Instead, it stays in the history, advancing
+forward by one position to the successor of the submitted line.
+
+Ctrl-X, Enter can be used to conveniently submit a range of lines
+from the history, one by one, in their original order.
+
 .NP* Insert Previous Word
 
 The equivalent command sequences Ctrl-X, w and Ctrl-X, Ctrl-W insert