Add potentially missing null checks

This fixes a potential regression introduced in
34b8e38 When that commit was
done some instanceof checks were removed.
The result of removing the instanceof checks had the side effect
of removing the implicit null check that instanceof essentially
does.

This change restores the null checks for all the instanceofs that
were removed in 34b8e38

Author: jonahgraham

apitools/org.eclipse.pde.api.tools/src/org/eclipse/pde/api/tools/internal/util/Signatures.java

@@ -584,15 +584,18 @@ public static String getTypeSignature(Type type, boolean erased) {
 							}
 							if (typeParameters != null) {
 								for (TypeParameter typeParameter : typeParameters) {
-									if (fullyQualifiedName.equals(typeParameter.getName().getFullyQualifiedName())) {
-										if (typeParameter.typeBounds().isEmpty()) {
-											yield Signature.createTypeSignature("Object", false); //$NON-NLS-1$
-										} else {
-											// the erasure of a type
-											// variable is the erasure of
-											// its leftmost bound
-											Type bound = (Type) typeParameter.typeBounds().get(0);
-											yield getTypeSignature(bound, erased);
+									if (typeParameter != null) {
+										if (fullyQualifiedName
+												.equals(typeParameter.getName().getFullyQualifiedName())) {
+											if (typeParameter.typeBounds().isEmpty()) {
+												yield Signature.createTypeSignature("Object", false); //$NON-NLS-1$
+											} else {
+												// the erasure of a type
+												// variable is the erasure of
+												// its leftmost bound
+												Type bound = (Type) typeParameter.typeBounds().get(0);
+												yield getTypeSignature(bound, erased);
+											}
 										}
 									}
 								}

ui/org.eclipse.pde.core/src/org/eclipse/pde/internal/core/target/P2TargetUtils.java

@@ -1554,8 +1554,10 @@ private void findProfileRepos(Set<URI> additionalRepos) {
 			Collection<IRepositoryReference> repos = new org.eclipse.equinox.internal.p2.engine.ProfileMetadataRepository(
 					getGlobalAgent(), dataArea, null).getReferences();
 			for (IRepositoryReference reference : repos) {
-				if (reference.getType() == IRepository.TYPE_ARTIFACT && reference.getLocation() != null) {
-					additionalRepos.add(reference.getLocation());
+				if (reference != null) {
+					if (reference.getType() == IRepository.TYPE_ARTIFACT && reference.getLocation() != null) {
+						additionalRepos.add(reference.getLocation());
+					}
 				}
 			}
 		} catch (CoreException e) {