retire qsort in favor of std::sort, std::stable_sort (GPSBabel#888)

* replace qsort with std::sort or std::stable_sort

* add test for duplicate filter using gc_data exported dates.

* fix reference file permissions.

* fix smplrout sort bug that shows up on macos with std::sort.

the compare function has always generated incorrect values when
both objects are HUGEVAL. The historic function worked with qsort
everywhere, worked with std::sort on linux and windows, but failed
with std::sort on macos.

duplicate.cc

@@ -19,8 +19,8 @@
 
  */
 
+#include <algorithm>            // for stable_sort
 #include <cstdio>               // for sprintf
-#include <cstdlib>              // for qsort
 #include <cstring>              // for memset, strncpy
 
 #include <QDateTime>            // for QDateTime
@@ -114,30 +114,6 @@ be zero so the sort will end up being an expensive no-op (expensive
 because, sadly, quicksort can be O(n^2) on presorted elements.)
 */
 
-
-int DuplicateFilter::compare(const void* a, const void* b)
-{
-  const wpt_ptr* wa = (wpt_ptr*)a;
-  const wpt_ptr* wb = (wpt_ptr*)b;
-
-  if (wa->wpt->gc_data->exported < wb->wpt->gc_data->exported) {
-    return 1;
-  } else if (wa->wpt->gc_data->exported > wb->wpt->gc_data->exported) {
-    return -1;
-  }
-
-  /* If the exported dates are the same, sort by index. */
-  if (wa->index < wb->index) {
-    return -1;
-  } else if (wa->index > wb->index) {
-    return 1;
-  }
-
-  /* If index and date are the same, it's the same element. */
-  return 0;
-
-}
-
 void DuplicateFilter::process()
 {
   btree_node* btmp = nullptr;
@@ -150,22 +126,14 @@ void DuplicateFilter::process()
   } dupe;
   Waypoint* delwpt = nullptr;
 
-  int ct = waypt_count();
-
-  auto* htable = (wpt_ptr*) xmalloc(ct * sizeof(wpt_ptr));
-  wpt_ptr* bh = htable;
+  auto htable = *global_waypoint_list;
 
-  int i = 0;
-  foreach (Waypoint* waypointp, *global_waypoint_list) {
-    bh->wpt = waypointp;
-    bh->index = i;
-    i ++;
-    bh ++;
-  }
-  qsort(htable, ct, sizeof(*htable), compare);
+  auto compare_lambda = [](const Waypoint* wa, const Waypoint* wb)->bool {
+    return wa->gc_data->exported > wb->gc_data->exported;
+  };
+  std::stable_sort(htable.begin(), htable.end(), compare_lambda);
 
-  for (i=0; i<ct; i++) {
-    auto* waypointp = htable[i].wpt;
+  for (Waypoint* waypointp : htable) {
 
     memset(&dupe, '\0', sizeof(dupe));
 
@@ -218,7 +186,6 @@ void DuplicateFilter::process()
 
   delete delwpt;
 
-  xfree(htable);
   if (sup_tree) {
     free_tree(sup_tree);
   }

duplicate.h

@@ -73,13 +73,6 @@ class DuplicateFilter:public Filter
   static btree_node* addnode(btree_node* tree, btree_node* newnode, btree_node** oldnode);
   void free_tree(btree_node* tree);
 
-  struct wpt_ptr {
-    Waypoint* wpt;
-    int index;
-  };
-
-  static int compare(const void* a, const void* b);
-
 };
 #endif
 #endif // DUPLICATE_H_INCLUDED_

garmin_txt.cc

@@ -23,11 +23,12 @@
 #include "defs.h"
 
 #if CSVFMTS_ENABLED
+#include <algorithm>               // for sort
 #include <cctype>                  // for toupper
 #include <cmath>                   // for fabs, floor
 #include <cstdio>                  // for NULL, snprintf, sscanf
 #include <cstdint>
-#include <cstdlib>                 // for atoi, abs, qsort
+#include <cstdlib>                 // for atoi, abs
 #include <cstring>                 // for memset, strstr, strcat, strchr, strlen, strcmp, strcpy, strncpy
 #include <ctime>                   // for gmtime, localtime, strftime
 
@@ -240,15 +241,6 @@ enum_waypt_cb(const Waypoint* wpt)
 
 }
 
-static int
-sort_waypt_cb(const void* a, const void* b)
-{
-  const Waypoint* wa = *(Waypoint**)a;
-  const Waypoint* wb = *(Waypoint**)b;
-  return wa->shortname.compare(wb->shortname, Qt::CaseInsensitive);
-}
-
-
 /* common route and track pre-work */
 
 static void
@@ -834,17 +826,19 @@ garmin_txt_write()
 
   if (waypoints > 0) {
     wpt_a_ct = 0;
-    wpt_a = (const Waypoint**)xcalloc(waypoints, sizeof(*wpt_a));
+    wpt_a = new const Waypoint*[waypoints]{};
     waypt_disp_all(enum_waypt_cb);
     route_disp_all(nullptr, nullptr, enum_waypt_cb);
-    qsort(wpt_a, waypoints, sizeof(*wpt_a), sort_waypt_cb);
+    auto sort_waypt_lambda = [](const Waypoint* wa, const Waypoint* wb)->bool {
+      return wa->shortname.compare(wb->shortname, Qt::CaseInsensitive) < 0;
+    };
+    std::sort(wpt_a, wpt_a + waypoints, sort_waypt_lambda);
 
     *fout << QString::asprintf("Header\t%s\r\n\r\n", headers[waypt_header]);
     for (int i = 0; i < waypoints; i++) {
-      const Waypoint* wpt = wpt_a[i];
-      write_waypt(wpt);
+      write_waypt(wpt_a[i]);
     }
-    xfree(wpt_a);
+    delete[] wpt_a;
 
     route_idx = 0;
     route_info = (info_t*) xcalloc(route_count(), sizeof(info_t));

reference/duplicate_exported_1.csv

@@ -0,0 +1,5 @@
+No,Latitude,Longitude,Name,Exported
+1,40.0,-105.1,"zero",2015/06/24 00:00:00
+1,40.0,-105.2,"one",2015/06/25 00:00:01
+1,40.0,-105.2,"two",2015/06/25 00:00:00
+1,40.0,-105.1,"three",2015/06/24 00:00:01

reference/duplicate_exported_1~csv.csv

@@ -0,0 +1,3 @@
+No,Latitude,Longitude,Name,Exported
+1,40.000000,-105.200000,"one","2015/06/25 00:00:01"
+2,40.000000,-105.100000,"three","2015/06/24 00:00:01"

reference/duplicate_exported_2.csv

@@ -0,0 +1,5 @@
+No,Latitude,Longitude,Name,Exported
+1,40.0,-105.1,"zero",2015/06/24 00:00:02
+1,40.0,-105.2,"one",2015/06/25 00:00:01
+1,40.0,-105.2,"two",2015/06/25 00:00:02
+1,40.0,-105.1,"three",2015/06/24 00:00:01

reference/duplicate_exported_2~csv.csv

@@ -0,0 +1,3 @@
+No,Latitude,Longitude,Name,Exported
+1,40.000000,-105.100000,"zero","2015/06/24 00:00:02"
+2,40.000000,-105.200000,"two","2015/06/25 00:00:02"

smplrout.cc

@@ -56,7 +56,8 @@
 	2008/08/20: added "relative" option, (Carsten Allefeld, [email protected])
 */
 
-#include <cstdlib>              // for qsort, strtol
+#include <algorithm>            // for sort
+#include <cstdlib>              // for strtol
 #include <utility>              // for swap
 
 #include <QDateTime>            // for QDateTime
@@ -158,6 +159,9 @@ int SimplifyRouteFilter::compare_xte(const void* a, const void* b)
   const auto* xte_b = static_cast<const struct xte*>(b);
 
   if (HUGEVAL == xte_a->distance) {
+    if (HUGEVAL == xte_b->distance) {
+      return 0;
+    }
     return -1;
   }
 
@@ -238,7 +242,11 @@ void SimplifyRouteFilter::routesimple_tail(const route_head* rte)
 
 
   /* sort XTE array, lowest XTE last */
-  qsort(xte_recs, xte_count, sizeof(struct xte), compare_xte);
+  auto compare_xte_lambda = [](const xte& a, const xte& b)->bool {
+    return compare_xte(&a, &b) < 0;
+  };
+  std::sort(xte_recs, xte_recs + xte_count, compare_xte_lambda);
+
 
   for (i = 0; i < xte_count; i++) {
     xte_recs[i].intermed->xte_rec = xte_recs+i;

testo.d/duplicate.test

@@ -7,3 +7,8 @@ gpsbabel -i geo -f ${REFERENCE}/geocaching.loc -o csv -F ${TMPDIR}/filterdupe.cs
 gpsbabel -i geo -f ${REFERENCE}/geocaching.loc -f ${REFERENCE}/geocaching.loc -x duplicate,shortname \
 		-o csv -F ${TMPDIR}/filterdupe.csv2
 sort_and_compare ${TMPDIR}/filterdupe.csv1 ${TMPDIR}/filterdupe.csv2
+
+gpsbabel -i unicsv,utc -f ${REFERENCE}/duplicate_exported_1.csv -x duplicate,location -o unicsv,utc -F ${TMPDIR}/duplicate_exported_1~csv.csv
+compare ${REFERENCE}/duplicate_exported_1~csv.csv ${TMPDIR}/duplicate_exported_1~csv.csv
+gpsbabel -i unicsv,utc -f ${REFERENCE}/duplicate_exported_2.csv -x duplicate,location -o unicsv,utc -F ${TMPDIR}/duplicate_exported_2~csv.csv
+compare ${REFERENCE}/duplicate_exported_2~csv.csv ${TMPDIR}/duplicate_exported_2~csv.csv