diff --git a/src/celengine/dds.cpp b/src/celengine/dds.cpp
index 4b55c46898..820fc053e6 100644
--- a/src/celengine/dds.cpp
+++ b/src/celengine/dds.cpp
@@ -89,55 +89,47 @@ GLvoid *decompressDXTc(GLsizei width, GLsizei height, GLenum format, int transpa
     // decompress a DXTc image
     // get pixel size of decompressed image => fixed RGBA
     int pixelsize = 4;
-/*    if (format==COMPRESSED_RGB_S3TC_DXT1_EXT)
-        pixelsize = 3;*/
     // TODO: check with the size of the input data stream if the stream is in fact decompressed
     // alloc memory
-    GLvoid *pixels = malloc(((width+3)&~3)*((height+3)&~3)*pixelsize);
+    GLvoid *pixels = malloc(((width + 3) & ~3) * ((height + 3) & ~3) * pixelsize);
     // decompress loop
     int blocksize = 0;
-    switch (format) {
-        case GL_COMPRESSED_RGB_S3TC_DXT1_EXT:
-        case GL_COMPRESSED_SRGB_S3TC_DXT1_EXT:
-        case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
-        case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT1_EXT:
-            blocksize = 8;
-            break;
-        case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT:
-        case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT:
-        case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT:
-        case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT:
-            blocksize = 16;
-            break;
+#define DDS_MAX_BLOCK_SIZE      16
+    switch (format)
+    {
+    case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
+        blocksize = 8;
+        break;
+    case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT:
+    case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT:
+        blocksize = 16;
+        break;
     }
-    uintptr_t *block = (uintptr_t *)malloc(sizeof(blocksize));
-    for (int y=0; y<height; y+=4) {
-        for (int x=0; x<width; x+=4) {
-            if (!in.good()) {
-                free(block);
+    char block[DDS_MAX_BLOCK_SIZE]; // enough to hold DXT1/3/5 blocks
+    for (int y = 0; y < height; y += 4)
+    {
+        for (int x = 0; x < width; x += 4)
+        {
+            if (!in.good())
+            {
                 free(pixels);
                 return nullptr;
             }
-            in.read(reinterpret_cast<char*>(block), blocksize);
-            switch(format) {
-                case GL_COMPRESSED_RGB_S3TC_DXT1_EXT:
-                case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
-                case GL_COMPRESSED_SRGB_S3TC_DXT1_EXT:
-                case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT1_EXT:
-                    DecompressBlockDXT1(x, y, width, (uint8_t*)block, transparent0, simpleAlpha, complexAlpha, (uint32_t *)pixels);
-                    break;
-                case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT:
-                case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT:
-                    DecompressBlockDXT3(x, y, width, (uint8_t*)block, transparent0, simpleAlpha, complexAlpha, (uint32_t *)pixels);
-                    break;
-                case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT:
-                case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT:
-                    DecompressBlockDXT5(x, y, width, (uint8_t*)block, transparent0, simpleAlpha, complexAlpha, (uint32_t *)pixels);
-                    break;
+            in.read(block, blocksize);
+            switch(format)
+            {
+            case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
+                DecompressBlockDXT1(x, y, width, (uint8_t*)block, transparent0, simpleAlpha, complexAlpha, (uint32_t *)pixels);
+                break;
+            case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT:
+                DecompressBlockDXT3(x, y, width, (uint8_t*)block, transparent0, simpleAlpha, complexAlpha, (uint32_t *)pixels);
+                break;
+            case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT:
+                DecompressBlockDXT5(x, y, width, (uint8_t*)block, transparent0, simpleAlpha, complexAlpha, (uint32_t *)pixels);
+                break;
             }
         }
     }
-    free(block);
     return pixels;
 }
 
@@ -262,10 +254,10 @@ Image* LoadDDSImage(const fs::path& filename)
                 tmp = decompressDXTc(nw, nh, format, transparent0, &simpleAlpha, &complexAlpha, in);
                 if (tmp != nullptr)
                 {
-                    pixels = malloc(4*ddsd.width*ddsd.height);
+                    pixels = malloc(4 * ddsd.width * ddsd.height);
                     // crop
                     for (int y=0; y<ddsd.height; y++)
-                        memcpy((char *)pixels+y*ddsd.width*4, (char *)tmp+y*nw*4, ddsd.width*4);
+                        memcpy((char *)pixels + y * ddsd.width * 4, (char *)tmp + y * nw * 4, ddsd.width * 4);
                     free(tmp);
                 }
             }
diff --git a/src/celengine/galaxy.cpp b/src/celengine/galaxy.cpp
index f68cc94f8d..d7f66dfbea 100644
--- a/src/celengine/galaxy.cpp
+++ b/src/celengine/galaxy.cpp
@@ -230,6 +230,9 @@ bool Galaxy::pick(const Ray3d& ray,
                   double& distanceToPicker,
                   double& cosAngleToBoundCenter) const
 {
+    if (form == nullptr)
+        return false;
+
     if (!isVisible())
         return false;
 
diff --git a/src/celestia/celestiacore.cpp b/src/celestia/celestiacore.cpp
index fc9c904fc4..d859a66f9d 100644
--- a/src/celestia/celestiacore.cpp
+++ b/src/celestia/celestiacore.cpp
@@ -394,7 +394,7 @@ void CelestiaCore::mouseButtonUp(float x, float y, int button)
     setViewChanged();
 
     // Four pixel tolerance for picking
-    float pickTolerance = sim->getActiveObserver()->getFOV() / height * 4.0f;
+    float pickTolerance = sim->getActiveObserver()->getFOV() / height * this->pickTolerance;
 
     if (resizeSplit != nullptr)
     {
@@ -2181,6 +2181,16 @@ void CelestiaCore::setSafeAreaInsets(int left, int top, int right, int bottom)
     safeAreaInsets = { left, top, right, bottom };
 }
 
+float CelestiaCore::getPickTolerance() const
+{
+    return pickTolerance;
+}
+
+void CelestiaCore::setPickTolerance(float newPickTolerance)
+{
+    pickTolerance = newPickTolerance;
+}
+
 // Return true if anything changed that requires re-rendering. Otherwise, we
 // can skip rendering, keep the GPU idle, and save power.
 bool CelestiaCore::viewUpdateRequired() const
diff --git a/src/celestia/celestiacore.h b/src/celestia/celestiacore.h
index 7736d7fe16..895f457819 100644
--- a/src/celestia/celestiacore.h
+++ b/src/celestia/celestiacore.h
@@ -286,6 +286,8 @@ class CelestiaCore // : public Watchable<CelestiaCore>
     int getDistanceToScreen() const;
     void setDistanceToScreen(int);
     void setSafeAreaInsets(int left, int top, int right, int bottom);
+    float getPickTolerance() const;
+    void setPickTolerance(float);
 
     void setFOVFromZoom();
     void setZoomFromFOV();
@@ -467,6 +469,8 @@ class CelestiaCore // : public Watchable<CelestiaCore>
     int screenDpi{ 96 };
     int distanceToScreen{ 400 };
 
+    float pickTolerance { 4.0f };
+
     unique_ptr<ViewportEffect> viewportEffect { nullptr };
     bool isViewportEffectUsed { false };