Measure distance from pad center, not pad hull.

Otherwise we think the wrong end of really short track segments is
connected to the pad, leaving the other end dangling.

Fixes https://gitlab.com/kicad/code/kicad/issues/8909

pcbnew/connectivity/connectivity_data.cpp

@@ -36,6 +36,7 @@
 #include <connectivity/from_to_cache.h>
 
 #include <ratsnest/ratsnest_data.h>
+#include <trigo.h>
 
 CONNECTIVITY_DATA::CONNECTIVITY_DATA()
 {
@@ -586,6 +587,25 @@ void CONNECTIVITY_DATA::GetUnconnectedEdges( std::vector<CN_EDGE>& aEdges) const
 }
 
 
+static int getMinDist( BOARD_CONNECTED_ITEM* aItem, const wxPoint& aPoint )
+{
+    switch( aItem->Type() )
+    {
+    case PCB_TRACE_T:
+    case PCB_ARC_T:
+    {
+        PCB_TRACK* track = static_cast<PCB_TRACK*>( aItem );
+
+        return std::min( GetLineLength( track->GetStart(), aPoint ),
+                         GetLineLength( track->GetEnd(), aPoint ) );
+    }
+
+    default:
+        return GetLineLength( aItem->GetPosition(), aPoint );
+    }
+}
+
+
 bool CONNECTIVITY_DATA::TestTrackEndpointDangling( PCB_TRACK* aTrack, wxPoint* aPos )
 {
     std::list<CN_ITEM*> items = GetConnectivityAlgo()->ItemEntry( aTrack ).GetItems();
@@ -623,14 +643,12 @@ bool CONNECTIVITY_DATA::TestTrackEndpointDangling( PCB_TRACK* aTrack, wxPoint* a
 
             std::shared_ptr<SHAPE> shape = item->GetEffectiveShape( layer );
 
-            int  startDist;
+            bool hitStart = shape->Collide( aTrack->GetStart(), accuracy );
-            int  endDist;
+            bool hitEnd = shape->Collide( aTrack->GetEnd(), accuracy );
-            bool hitStart = shape->Collide( aTrack->GetStart(), accuracy, &startDist );
-            bool hitEnd = shape->Collide( aTrack->GetEnd(), accuracy, &endDist );
 
             if( hitStart && hitEnd )
             {
-                if( startDist <= endDist )
+                if( getMinDist( item, aTrack->GetStart() ) < getMinDist( item, aTrack->GetEnd() ) )
                     start_count++;
                 else
                     end_count++;

pcbnew/connectivity/connectivity_items.cpp

@@ -147,7 +147,6 @@ const VECTOR2I CN_ITEM::GetAnchor( int n ) const
 
     default:
         assert( false );
-        break;
     }
 
     return pt0;

qa/data/issue6879.kicad_pcb

@@ -1,4 +1,4 @@
-(kicad_pcb (version 20201220) (generator pcbnew)
+(kicad_pcb (version 20210722) (generator pcbnew)
 
   (general
     (thickness 1.6)
@@ -51,6 +51,7 @@
       (copper_finish "None")
       (dielectric_constraints no)
     )
+    (pad_to_mask_clearance 0)
     (pcbplotparams
       (layerselection 0x00010fc_ffffffff)
       (disableapertmacros false)
@@ -68,6 +69,9 @@
       (hpglpennumber 1)
       (hpglpenspeed 20)
       (hpglpendiameter 15.000000)
+      (dxfpolygonmode true)
+      (dxfimperialunits true)
+      (dxfusepcbnewfont true)
       (psnegative false)
       (psa4output false)
       (plotreference true)
@@ -83,7 +87,6 @@
     )
   )
 
-
   (net 0 "")
   (net 1 "Net-(C1-Pad2)")
   (net 2 "Net-(C1-Pad1)")
@@ -111,7 +114,7 @@
     )
     (fp_circle (center 0 0) (end 2.8 0) (layer "Cmts.User") (width 0.15) (fill none) (tstamp 533cb978-4c67-4904-86ed-173bc2ff1b45))
     (fp_circle (center 0 0) (end 3.05 0) (layer "F.CrtYd") (width 0.05) (fill none) (tstamp c08b7dbb-612b-43e9-a6cc-d4e66c1ea404))
-    (pad "1" thru_hole circle (at 0 0) (size 5.6 5.6) (drill 3.2) (layers *.Cu *.Mask) (tstamp cfbc907d-8a25-46e9-a224-6b8152fa214f))
+    (pad "1" thru_hole circle locked (at 0 0) (size 5.6 5.6) (drill 3.2) (layers *.Cu *.Mask) (tstamp cfbc907d-8a25-46e9-a224-6b8152fa214f))
   )
 
   (footprint "MountingHole:MountingHole_3.2mm_M3_DIN965_Pad" (layer "F.Cu")
@@ -137,7 +140,7 @@
     )
     (fp_circle (center 0 0) (end 2.8 0) (layer "Cmts.User") (width 0.15) (fill none) (tstamp 7f8e2e3b-3a66-47a9-a58a-28516317d286))
     (fp_circle (center 0 0) (end 3.05 0) (layer "F.CrtYd") (width 0.05) (fill none) (tstamp ee76c024-e387-4561-9d80-268c0015a52b))
-    (pad "1" thru_hole circle (at 0 0) (size 5.6 5.6) (drill 3.2) (layers *.Cu *.Mask) (tstamp b5c3eb60-d01c-403e-abf7-cd1ddd2c14be))
+    (pad "1" thru_hole circle locked (at 0 0) (size 5.6 5.6) (drill 3.2) (layers *.Cu *.Mask) (tstamp b5c3eb60-d01c-403e-abf7-cd1ddd2c14be))
   )
 
   (footprint "MountingHole:MountingHole_3.2mm_M3" (layer "F.Cu")
@@ -163,7 +166,7 @@
     )
     (fp_circle (center 0 0) (end 3.2 0) (layer "Cmts.User") (width 0.15) (fill none) (tstamp d4901f12-4dae-4cd4-9bb1-5d962ba4e57d))
     (fp_circle (center 0 0) (end 3.45 0) (layer "F.CrtYd") (width 0.05) (fill none) (tstamp 3d371e65-4ed5-435b-8cfc-b2bca6d607db))
-    (pad "1" np_thru_hole circle (at 0 0) (size 3.2 3.2) (drill 3.2) (layers *.Cu *.Mask) (tstamp 30bed439-ee98-4fbc-9d75-6c7a47f1e483))
+    (pad "1" np_thru_hole circle locked (at 0 0) (size 3.2 3.2) (drill 3.2) (layers *.Cu *.Mask) (tstamp 30bed439-ee98-4fbc-9d75-6c7a47f1e483))
   )
 
   (footprint "MountingHole:MountingHole_3.2mm_M3" (layer "F.Cu")
@@ -189,7 +192,7 @@
     )
     (fp_circle (center 0 0) (end 3.2 0) (layer "Cmts.User") (width 0.15) (fill none) (tstamp ad1a6974-bb9c-4845-bf1b-4eb349a7b5f9))
     (fp_circle (center 0 0) (end 3.45 0) (layer "F.CrtYd") (width 0.05) (fill none) (tstamp 7495fc84-6ec6-45ca-9071-d10637312859))
-    (pad "1" np_thru_hole circle (at 0 0) (size 3.2 3.2) (drill 3.2) (layers *.Cu *.Mask) (tstamp 3c6562ef-6330-45e0-b952-0a82c3116b50))
+    (pad "1" np_thru_hole circle locked (at 0 0) (size 3.2 3.2) (drill 3.2) (layers *.Cu *.Mask) (tstamp 3c6562ef-6330-45e0-b952-0a82c3116b50))
   )
 
   (footprint "Connector_JST:JST_XH_B2B-XH-A_1x02_P2.50mm_Vertical" (layer "F.Cu")
@@ -249,9 +252,9 @@
     (fp_line (start -2.45 3.4) (end 4.95 3.4) (layer "F.Fab") (width 0.1) (tstamp b6e260db-b404-43d2-9d13-3d72bf702940))
     (fp_line (start -0.625 -2.35) (end 0 -1.35) (layer "F.Fab") (width 0.1) (tstamp d901e84b-f741-4b4a-93a0-440497371c23))
     (fp_line (start 4.95 3.4) (end 4.95 -2.35) (layer "F.Fab") (width 0.1) (tstamp e9b8a997-2bef-41da-8437-468ed47a22a5))
-    (pad "1" thru_hole roundrect (at 0 0 90) (size 1.7 2) (drill 1) (layers *.Cu *.Mask) (roundrect_rratio 0.147059)
+    (pad "1" thru_hole roundrect locked (at 0 0 90) (size 1.7 2) (drill 1) (layers *.Cu *.Mask) (roundrect_rratio 0.147059)
       (net 2 "Net-(C1-Pad1)") (pinfunction "Pin_1") (tstamp 3bbb4641-3942-4c40-a8f5-028930bd1924))
-    (pad "2" thru_hole oval (at 2.5 0 90) (size 1.7 2) (drill 1) (layers *.Cu *.Mask)
+    (pad "2" thru_hole oval locked (at 2.5 0 90) (size 1.7 2) (drill 1) (layers *.Cu *.Mask)
       (net 1 "Net-(C1-Pad2)") (pinfunction "Pin_2") (tstamp 63fbe990-c88a-466e-a812-693fc90734fb))
     (model "${KISYS3DMOD}/Connector_JST.3dshapes/JST_XH_B2B-XH-A_1x02_P2.50mm_Vertical.wrl"
       (offset (xyz 0 0 0))
@@ -480,9 +483,9 @@
     (fp_line (start -1.288861 -2.6875) (end -1.288861 -1.6875) (layer "F.Fab") (width 0.1) (tstamp b6c4deb0-fbd8-49e2-b960-ea1125602887))
     (fp_line (start -1.788861 -2.1875) (end -0.788861 -2.1875) (layer "F.Fab") (width 0.1) (tstamp fae7d5ad-c3c5-4fcb-bcd4-fc23876b2809))
     (fp_circle (center 2.5 0) (end 7.5 0) (layer "F.Fab") (width 0.1) (fill none) (tstamp 5b63012c-bc76-4056-91fe-35f030921af3))
-    (pad "1" thru_hole rect (at 0 0 90) (size 2 2) (drill 1) (layers *.Cu *.Mask)
+    (pad "1" thru_hole rect locked (at 0 0 90) (size 2 2) (drill 1) (layers *.Cu *.Mask)
       (net 2 "Net-(C1-Pad1)") (tstamp d1b41142-17bd-4982-b9b6-d4a10278ed3d))
-    (pad "2" thru_hole circle (at 5 0 90) (size 2 2) (drill 1) (layers *.Cu *.Mask)
+    (pad "2" thru_hole circle locked (at 5 0 90) (size 2 2) (drill 1) (layers *.Cu *.Mask)
       (net 1 "Net-(C1-Pad2)") (tstamp a9206b2b-cfcc-466f-81ba-e763a0afb122))
     (model "${KISYS3DMOD}/Capacitor_THT.3dshapes/CP_Radial_D10.0mm_P5.00mm.wrl"
       (offset (xyz 0 0 0))
@@ -500,7 +503,6 @@
   (segment (start 172.58 104.67) (end 180 97.25) (width 1) (layer "F.Cu") (net 1) (tstamp dc290915-31f5-4f0b-ab64-8739fddbcb76))
   (segment (start 167.20001 103.93001) (end 167.94 104.67) (width 1) (layer "F.Cu") (net 1) (tstamp f6868b20-ef70-414e-925a-2c4c9f34cb51))
   (segment (start 165.5 101.25) (end 165.5 106.75) (width 1) (layer "F.Cu") (net 2) (tstamp 2404edcf-bf9e-4398-926e-3c87149c9e87))
-  (segment (start 165.5 101.25) (end 165.25 101.25) (width 0.25) (layer "F.Cu") (net 2) (tstamp 310f0fbf-62d2-41b4-a487-1a46623d436e))
   (segment (start 165.5 106.75) (end 170 111.25) (width 1) (layer "F.Cu") (net 2) (tstamp 3644bbd8-a9d9-4c8e-8dd6-6a37d4866b02))
   (segment (start 170 111.25) (end 171 111.25) (width 1) (layer "F.Cu") (net 2) (tstamp 3af17702-004e-460b-a2d0-f0d3d8066df2))
   (segment (start 171 111.25) (end 180 102.25) (width 1) (layer "F.Cu") (net 2) (tstamp 55ddfac6-70ec-48ed-90ad-fc1178b0e3cc))

qa/data/issue6879.kicad_pro

@@ -88,12 +88,12 @@
         "silk_overlap": "error",
         "skew_out_of_range": "error",
         "too_many_vias": "error",
-        "track_dangling": "ignore",
+        "track_dangling": "warning",
         "track_width": "error",
         "tracks_crossing": "error",
         "unconnected_items": "error",
         "unresolved_variable": "error",
-        "via_dangling": "ignore",
+        "via_dangling": "warning",
         "zone_has_empty_net": "error",
         "zones_intersect": "error"
       },