diff --git a/core/org.eclipse.cdt.ui.tests/ui/org/eclipse/cdt/ui/tests/text/contentassist2/AbstractContentAssistTest.java b/core/org.eclipse.cdt.ui.tests/ui/org/eclipse/cdt/ui/tests/text/contentassist2/AbstractContentAssistTest.java
index a696b767845..b0988c88323 100644
--- a/core/org.eclipse.cdt.ui.tests/ui/org/eclipse/cdt/ui/tests/text/contentassist2/AbstractContentAssistTest.java
+++ b/core/org.eclipse.cdt.ui.tests/ui/org/eclipse/cdt/ui/tests/text/contentassist2/AbstractContentAssistTest.java
@@ -50,7 +50,7 @@ public abstract class AbstractContentAssistTest extends BaseUITestCase {
 	public static final int COMPARE_DISP_STRINGS = 1;
 	public static final int COMPARE_REP_STRINGS = 2;
 	
-	private ICProject fCProject;
+	protected ICProject fCProject;
 	private IFile fCFile;
 	protected ITextEditor fEditor;
 	private boolean fIsCpp;
diff --git a/core/org.eclipse.cdt.ui.tests/ui/org/eclipse/cdt/ui/tests/text/contentassist2/CompletionTests.java b/core/org.eclipse.cdt.ui.tests/ui/org/eclipse/cdt/ui/tests/text/contentassist2/CompletionTests.java
index 8be873987d0..a7a4d991d0f 100644
--- a/core/org.eclipse.cdt.ui.tests/ui/org/eclipse/cdt/ui/tests/text/contentassist2/CompletionTests.java
+++ b/core/org.eclipse.cdt.ui.tests/ui/org/eclipse/cdt/ui/tests/text/contentassist2/CompletionTests.java
@@ -21,6 +21,7 @@ import org.eclipse.jface.text.IDocument;
 
 import org.eclipse.cdt.core.CCorePlugin;
 import org.eclipse.cdt.core.testplugin.util.BaseTestCase;
+import org.eclipse.cdt.core.testplugin.util.TestSourceReader;
 
 /**
  * A collection of code completion tests.
@@ -895,4 +896,30 @@ public class CompletionTests extends AbstractContentAssistTest {
 		final String[] expected= new String[0];
 		assertCompletionResults(fCursorOffset, expected, AbstractContentAssistTest.COMPARE_REP_STRINGS);
 	}
+	
+	
+	// #ifdef __cplusplus__
+	// extern "C" {
+	// #endif
+	// void c_linkage();
+	// #ifdef __cplusplus__
+	// }
+	// #endif
+	
+	// #include "header191315.h"
+	
+	// #include "header191315.h"
+	// void xxx() { c_lin/*cursor*/
+	public void testExtenC_bug191315() throws Exception {
+		StringBuffer[] content= getContentsForTest(3);
+		createFile(fProject, "header191315.h", content[0].toString());
+		createFile(fProject, "source191315.c", content[0].toString());
+		createFile(fProject, "source191315.cpp", content[0].toString());
+		IFile dfile= createFile(fProject, "header191315.h", content[0].toString());
+		TestSourceReader.waitUntilFileIsIndexed(CCorePlugin.getIndexManager().getIndex(fCProject), dfile, 8000);
+		final String[] expected= {
+			"c_linkage()"
+		};
+		assertCompletionResults(fCursorOffset, expected, AbstractContentAssistTest.COMPARE_REP_STRINGS);
+	}
 }
diff --git a/core/org.eclipse.cdt.ui.tests/ui/org/eclipse/cdt/ui/tests/text/contentassist2/CompletionTests_PlainC.java b/core/org.eclipse.cdt.ui.tests/ui/org/eclipse/cdt/ui/tests/text/contentassist2/CompletionTests_PlainC.java
index 47fa7d4bc1f..9353283a375 100644
--- a/core/org.eclipse.cdt.ui.tests/ui/org/eclipse/cdt/ui/tests/text/contentassist2/CompletionTests_PlainC.java
+++ b/core/org.eclipse.cdt.ui.tests/ui/org/eclipse/cdt/ui/tests/text/contentassist2/CompletionTests_PlainC.java
@@ -21,6 +21,7 @@ import org.eclipse.jface.text.IDocument;
 
 import org.eclipse.cdt.core.CCorePlugin;
 import org.eclipse.cdt.core.testplugin.util.BaseTestCase;
+import org.eclipse.cdt.core.testplugin.util.TestSourceReader;
 
 /**
  * Completion tests for plain C.
@@ -188,4 +189,29 @@ public class CompletionTests_PlainC extends AbstractContentAssistTest {
 		final String[] expected= new String[0];
 		assertCompletionResults(expected);
 	}
+	
+	// #ifdef __cplusplus__
+	// extern "C" {
+	// #endif
+	// void c_linkage();
+	// #ifdef __cplusplus__
+	// }
+	// #endif
+	
+	// #include "header191315.h"
+	
+	// #include "header191315.h"
+	// void xxx() { c_lin/*cursor*/
+	public void testExtenC_bug191315() throws Exception {
+		StringBuffer[] content= getContentsForTest(3);
+		createFile(fProject, "header191315.h", content[0].toString());
+		createFile(fProject, "source191315.c", content[0].toString());
+		createFile(fProject, "source191315.cpp", content[0].toString());
+		IFile dfile= createFile(fProject, "header191315.h", content[0].toString());
+		TestSourceReader.waitUntilFileIsIndexed(CCorePlugin.getIndexManager().getIndex(fCProject), dfile, 8000);
+		final String[] expected= {
+			"c_linkage(void)"
+		};
+		assertCompletionResults(expected);
+	}
 }