Merge branch 'release-boba' into masterupstream/fabian-merge-v4.0.0

# Conflicts:
#	circle.yml
#	include/mbgl/style/expression/let.hpp
#	platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/geometry/LatLngBounds.java
#	platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/maps/MapGestureDetector.java
#	platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/maps/MapKeyListener.java
#	platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/maps/MapView.java
#	platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/maps/MapboxMap.java
#	platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/maps/Projection.java
#	platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/maps/Transform.java
#	platform/android/MapboxGLAndroidSDK/src/test/java/com/mapbox/mapboxsdk/geometry/LatLngBoundsTest.java
#	platform/android/MapboxGLAndroidSDKTestApp/src/main/AndroidManifest.xml
#	platform/android/gradle/dependencies.gradle
#	platform/android/src/example_custom_layer.cpp
#	platform/android/src/geojson/point.cpp
#	platform/darwin/src/NSPredicate+MGLAdditions.mm
#	platform/darwin/test/MGLExpressionTests.mm
#	platform/ios/Mapbox-iOS-SDK-nightly-dynamic.podspec
#	platform/ios/Mapbox-iOS-SDK-symbols.podspec
#	platform/ios/Mapbox-iOS-SDK.podspec
#	platform/ios/app/MBXViewController.m
#	src/mbgl/renderer/layers/render_custom_layer.cpp
#	src/mbgl/style/conversion/filter.cpp
#	src/mbgl/style/expression/interpolate.cpp
#	src/mbgl/style/expression/value.cpp
#	test/style/filter.test.cpp

3 files changed, 10 insertions, 4 deletions

diff --git a/src/mbgl/layout/symbol_instance.cpp b/src/mbgl/layout/symbol_instance.cpp
index 6e152349ca..7dfa8edf43 100644
--- a/src/mbgl/layout/symbol_instance.cpp
+++ b/src/mbgl/layout/symbol_instance.cpp
@@ -27,7 +27,7 @@ SymbolInstance::SymbolInstance(Anchor& anchor_,
     anchor(anchor_),
     line(line_),
     index(index_),
-    hasText(shapedTextOrientations.first || shapedTextOrientations.second),
+    hasText(false),
     hasIcon(shapedIcon),
 
     // Create the collision features that will be used to check whether this symbol instance can be placed
@@ -48,6 +48,8 @@ SymbolInstance::SymbolInstance(Anchor& anchor_,
     if (shapedTextOrientations.second) {
         verticalGlyphQuads = getGlyphQuads(shapedTextOrientations.second, layout, textPlacement, positions);
     }
+    // 'hasText' depends on finding at least one glyph in the shaping that's also in the GlyphPositionMap
+    hasText = horizontalGlyphQuads.size() > 0 || verticalGlyphQuads.size() > 0;
 
     if (shapedTextOrientations.first && shapedTextOrientations.second) {
         writingModes = WritingModeType::Horizontal | WritingModeType::Vertical;
diff --git a/src/mbgl/layout/symbol_layout.cpp b/src/mbgl/layout/symbol_layout.cpp
index 3bf85407c6..82a9255824 100644
--- a/src/mbgl/layout/symbol_layout.cpp
+++ b/src/mbgl/layout/symbol_layout.cpp
@@ -126,7 +126,7 @@ SymbolLayout::SymbolLayout(const BucketParameters& parameters,
         
         if (hasText) {
             std::string u8string = layout.evaluate<TextField>(zoom, ft);
-            if (layout.get<TextField>().isConstant()) {
+            if (layout.get<TextField>().isConstant() && !leader.layout.get<TextField>().isExpression()) {
                 u8string = util::replaceTokens(u8string, getValue);
             }
             
@@ -159,7 +159,7 @@ SymbolLayout::SymbolLayout(const BucketParameters& parameters,
 
         if (hasIcon) {
             std::string icon = layout.evaluate<IconImage>(zoom, ft);
-            if (layout.get<IconImage>().isConstant()) {
+            if (layout.get<IconImage>().isConstant() && !leader.layout.get<IconImage>().isExpression()) {
                 icon = util::replaceTokens(icon, getValue);
             }
             ft.icon = icon;
diff --git a/src/mbgl/layout/symbol_projection.cpp b/src/mbgl/layout/symbol_projection.cpp
index 9e077e2532..ef669c6e19 100644
--- a/src/mbgl/layout/symbol_projection.cpp
+++ b/src/mbgl/layout/symbol_projection.cpp
@@ -240,7 +240,11 @@ namespace mbgl {
                                                             const PlacedSymbol& symbol,
                                                             const mat4& labelPlaneMatrix,
                                                             const bool returnTileDistance) {
-
+        if (symbol.glyphOffsets.empty()) {
+            assert(false);
+            return optional<std::pair<PlacedGlyph, PlacedGlyph>>();
+        }
+        
         const float firstGlyphOffset = symbol.glyphOffsets.front();
         const float lastGlyphOffset = symbol.glyphOffsets.back();;