diff --git a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/parser/scanner2/BaseScanner.java b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/parser/scanner2/BaseScanner.java
index 163b060f315..69717b91ff7 100644
--- a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/parser/scanner2/BaseScanner.java
+++ b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/parser/scanner2/BaseScanner.java
@@ -2839,6 +2839,23 @@ abstract class BaseScanner implements IScanner {
         }
         
         CodeReader reader = null;
+		// filename is an absolute path or it is a Linux absolute path on a windows machine
+		if (new File(filename).isAbsolute() || filename.startsWith("/")) { //$NON-NLS-1$
+		    reader = createReader( EMPTY_STRING, filename );
+		    if (reader != null) {
+		        pushContext(reader.buffer, new InclusionData(reader,
+		                createInclusionConstruct(fileNameArray,
+		                        reader.filename, local, startOffset,
+		                        startingLine, nameOffset,
+		                        nameEndOffset, nameLine, endOffset,
+		                        endLine, false)));
+		        return;
+		    }
+		    handleProblem(IProblem.PREPROCESSOR_INCLUSION_NOT_FOUND, startOffset,
+		            fileNameArray);
+		    return;
+		}
+        
         File currentDirectory = null;
         if (local || include_next) {
             // if the include is eclosed in quotes OR we are in an include_next
@@ -2893,23 +2910,6 @@ abstract class BaseScanner implements IScanner {
                 }
             }
         }
-        
-        // if not found by this point, and the inclusion is local, try just the 
-        // path as is (bug 91086)
-        
-        if( local && !include_next )
-        {
-            reader = createReader( EMPTY_STRING, filename );
-            if (reader != null) {
-                pushContext(reader.buffer, new InclusionData(reader,
-                        createInclusionConstruct(fileNameArray,
-                                reader.filename, local, startOffset,
-                                startingLine, nameOffset,
-                                nameEndOffset, nameLine, endOffset,
-                                endLine, false)));
-                return;
-            }            
-        }
         handleProblem(IProblem.PREPROCESSOR_INCLUSION_NOT_FOUND, startOffset,
                 fileNameArray);
     }
diff --git a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/parser/scanner2/ScannerUtility.java b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/parser/scanner2/ScannerUtility.java
index 0e89348d56a..bb31c564a41 100644
--- a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/parser/scanner2/ScannerUtility.java
+++ b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/parser/scanner2/ScannerUtility.java
@@ -84,7 +84,9 @@ public class ScannerUtility {
         if( ! path.equals( "" )) //$NON-NLS-1$
         {
             newPathBuffer.append( new File(path).getPath() );
-            newPathBuffer.append( File.separatorChar );
+
+			if (fileName.length() > 0 && fileName.toCharArray()[0] != File.separatorChar)
+				newPathBuffer.append( File.separatorChar );
         }
 		newPathBuffer.append( fileName );
 		//remove ".." and "." segments
diff --git a/core/org.eclipse.cdt.core/src/org/eclipse/cdt/core/parser/CodeReaderCache.java b/core/org.eclipse.cdt.core/src/org/eclipse/cdt/core/parser/CodeReaderCache.java
index 8030d75f3b8..c902946ce58 100644
--- a/core/org.eclipse.cdt.core/src/org/eclipse/cdt/core/parser/CodeReaderCache.java
+++ b/core/org.eclipse.cdt.core/src/org/eclipse/cdt/core/parser/CodeReaderCache.java
@@ -9,6 +9,8 @@
 
 package org.eclipse.cdt.core.parser;
 
+import java.io.File;
+
 import org.eclipse.cdt.internal.core.parser.ast.EmptyIterator;
 import org.eclipse.cdt.internal.core.util.ILRUCacheable;
 import org.eclipse.cdt.internal.core.util.LRUCache;
@@ -137,6 +139,11 @@ public class CodeReaderCache implements ICodeReaderCache {
 		
 		// not in the cache
 		if (ret == null) {
+			// for efficiency: check File.exists before ParserUtil#createReader()
+			// bug 100947 fix: don't want to attempt to create a code reader if there is no file for the key
+			if (!(new File(key).exists()))
+				return null;
+			
 			ret = ParserUtil.createReader(key, EmptyIterator.EMPTY_ITERATOR);
 			
 			if (cache.getSpaceLimit() > 0)