1 files changed, 82 insertions, 37 deletions

diff --git a/miscutils/less.c b/miscutils/less.c
index 2a1797c7b..5c53cbdbf 100644
--- a/miscutils/less.c
+++ b/miscutils/less.c
@@ -711,23 +711,6 @@ static void status_print(void)
         print_hilite(p);
 }
 
-static void cap_cur_fline(int nlines)
-{
-        int diff;
-        if (cur_fline < 0)
-                cur_fline = 0;
-        if (cur_fline + max_displayed_line > max_fline + TILDES) {
-                cur_fline -= nlines;
-                if (cur_fline < 0)
-                        cur_fline = 0;
-                diff = max_fline - (cur_fline + max_displayed_line) + TILDES;
-                /* As the number of lines requested was too large, we just move
-                 * to the end of the file */
-                if (diff > 0)
-                        cur_fline += diff;
-        }
-}
-
 static const char controls[] ALIGN1 =
         /* NUL: never encountered; TAB: not converted */
         /**/"\x01\x02\x03\x04\x05\x06\x07\x08"  "\x0a\x0b\x0c\x0d\x0e\x0f"
@@ -913,37 +896,98 @@ static void buffer_fill_and_print(void)
         buffer_print();
 }
 
+/* move cur_fline to a given line number, reading lines if necessary */
+static void goto_lineno(int target)
+{
+        if (target <= 0 ) {
+                cur_fline = 0;
+        }
+        else if (target > LINENO(flines[cur_fline])) {
+ retry:
+                while (LINENO(flines[cur_fline]) != target && cur_fline < max_fline)
+                        ++cur_fline;
+                /* target not reached but more input is available */
+                if (LINENO(flines[cur_fline]) != target && eof_error > 0) {
+                        read_lines();
+                        goto retry;
+                }
+        }
+        else {
+                /* search backwards through already-read lines */
+                while (LINENO(flines[cur_fline]) != target && cur_fline > 0)
+                        --cur_fline;
+        }
+}
+
+static void cap_cur_fline(void)
+{
+        if ((option_mask32 & FLAG_S)) {
+                if (cur_fline > max_fline)
+                        cur_fline = max_fline;
+                if (LINENO(flines[cur_fline]) + max_displayed_line > max_lineno + TILDES) {
+                        goto_lineno(max_lineno - max_displayed_line + TILDES);
+                        read_lines();
+                }
+        }
+        else {
+                if (cur_fline + max_displayed_line > max_fline + TILDES)
+                        cur_fline = max_fline - max_displayed_line + TILDES;
+                if (cur_fline < 0)
+                        cur_fline = 0;
+        }
+}
+
 /* Move the buffer up and down in the file in order to scroll */
 static void buffer_down(int nlines)
 {
-        cur_fline += nlines;
+        if ((option_mask32 & FLAG_S))
+                goto_lineno(LINENO(flines[cur_fline]) + nlines);
+        else
+                cur_fline += nlines;
         read_lines();
-        cap_cur_fline(nlines);
+        cap_cur_fline();
         buffer_fill_and_print();
 }
 
 static void buffer_up(int nlines)
 {
-        cur_fline -= nlines;
-        if (cur_fline < 0) cur_fline = 0;
+        if ((option_mask32 & FLAG_S)) {
+                goto_lineno(LINENO(flines[cur_fline]) - nlines);
+        }
+        else {
+                cur_fline -= nlines;
+                if (cur_fline < 0)
+                        cur_fline = 0;
+        }
         read_lines();
         buffer_fill_and_print();
 }
 
-static void buffer_line(int linenum)
+/* display a given line where the argument can be either an index into
+ * the flines array or a line number */
+static void buffer_to_line(int linenum, int is_lineno)
 {
-        if (linenum < 0)
-                linenum = 0;
-        cur_fline = linenum;
+        if (linenum <= 0)
+                cur_fline = 0;
+        else if (is_lineno)
+                goto_lineno(linenum);
+        else
+                cur_fline = linenum;
         read_lines();
-        if (linenum + max_displayed_line > max_fline)
-                linenum = max_fline - max_displayed_line + TILDES;
-        if (linenum < 0)
-                linenum = 0;
-        cur_fline = linenum;
+        cap_cur_fline();
         buffer_fill_and_print();
 }
 
+static void buffer_line(int linenum)
+{
+        buffer_to_line(linenum, FALSE);
+}
+
+static void buffer_lineno(int lineno)
+{
+        buffer_to_line(lineno, TRUE);
+}
+
 static void open_file_and_read_lines(void)
 {
         if (filename) {
@@ -1348,15 +1392,16 @@ static void number_process(int first_digit)
                 buffer_up(num);
                 break;
         case 'g': case '<': case 'G': case '>':
-                cur_fline = num + max_displayed_line;
-                read_lines();
-                buffer_line(num - 1);
+                buffer_lineno(num - 1);
                 break;
         case 'p': case '%':
-                num = num * (max_fline / 100); /* + max_fline / 2; */
-                cur_fline = num + max_displayed_line;
-                read_lines();
-                buffer_line(num);
+#if ENABLE_FEATURE_LESS_FLAGS
+                update_num_lines();
+                num = num * (num_lines > 0 ? num_lines : max_lineno) / 100;
+#else
+                num = num * max_lineno / 100;
+#endif
+                buffer_lineno(num);
                 break;
 #if ENABLE_FEATURE_LESS_REGEXP
         case 'n':