fix trace becoming broken line

main.c

@@ -421,7 +421,7 @@ void sweep(void)
 
  rewind:
   frequency_updated = FALSE;
-  delay = 4;
+  delay = 5;
 
   for (i = 0; i < sweep_points; i++) {
     set_frequency(frequencies[i]);
@@ -447,6 +447,7 @@ void sweep(void)
     if (frequency_updated)
       goto rewind;
   }
+  set_frequency(frequencies[0]);
 
   if (cal_status & CALSTAT_APPLY)
     apply_error_term();

plot.c

@@ -806,7 +806,7 @@ cell_drawline(int w, int h, int x0, int y0, int x1, int y1, int c)
 }
 
 int
-search_index(int x, int y, uint32_t index[101], int *i0, int *i1)
+search_index_range(int x, int y, uint32_t index[101], int *i0, int *i1)
 {
   int i, j;
   int head = 0;
@@ -843,7 +843,7 @@ search_index(int x, int y, uint32_t index[101], int *i0, int *i1)
 }
 
 int
-search_index_x(int x, uint32_t index[101], int *i0, int *i1)
+search_index_range_x(int x, uint32_t index[101], int *i0, int *i1)
 {
   int i, j;
   int head = 0;
@@ -852,12 +852,13 @@ search_index_x(int x, uint32_t index[101], int *i0, int *i1)
   i = 0;
   while (head < tail) {
     i = (head + tail) / 2;
+    if (x == CELL_X0(index[i]))
+      break;
+
     if (x < CELL_X0(index[i]))
       tail = i+1;
-    else if (x > CELL_X0(index[i]))
-      head = i;
     else
-      break;
+      head = i;
   }
 
   if (x != CELL_X0(index[i]))
@@ -1106,9 +1107,11 @@ draw_cell(int m, int n)
     if (trace[t].type == TRC_SMITH || trace[t].type == TRC_POLAR)
       continue;
     
-    if (search_index_x(x0, trace_index[t], &i0, &i1)) {
+    if (search_index_range_x(x0, trace_index[t], &i0, &i1)) {
       if (i0 > 0)
         i0--;
+      if (i1 < 101-1)
+        i1++;
       for (i = i0; i < i1; i++) {
         int x1 = CELL_X(trace_index[t][i]);
         int x2 = CELL_X(trace_index[t][i+1]);