diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index b30f01d0ad2..82521ec2935 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,9 @@
+2016-02-08  David Malcolm  <dmalcolm@redhat.com>
+
+	PR preprocessor/69664
+	* gcc.dg/cpp/trad/comment-2.c: Add expected column number.
+	* gcc.dg/cpp/warn-comments.c: Likewise.
+
 2016-02-08  Marek Polacek  <polacek@redhat.com>
 
 	PR c++/69688
diff --git a/gcc/testsuite/gcc.dg/cpp/trad/comment-2.c b/gcc/testsuite/gcc.dg/cpp/trad/comment-2.c
index 8d54e3a0f32..310f5694276 100644
--- a/gcc/testsuite/gcc.dg/cpp/trad/comment-2.c
+++ b/gcc/testsuite/gcc.dg/cpp/trad/comment-2.c
@@ -8,4 +8,4 @@
 
 /*
 
- /* { dg-warning "within comment" } */
+ /* { dg-warning "2: within comment" } */
diff --git a/gcc/testsuite/gcc.dg/cpp/warn-comments.c b/gcc/testsuite/gcc.dg/cpp/warn-comments.c
index 1cdf75cf273..bbe28215894 100644
--- a/gcc/testsuite/gcc.dg/cpp/warn-comments.c
+++ b/gcc/testsuite/gcc.dg/cpp/warn-comments.c
@@ -1,7 +1,7 @@
 // { dg-do preprocess }
 // { dg-options "-std=gnu99 -fdiagnostics-show-option -Wcomments" }
 
-/* /* */  // { dg-warning "\"\.\*\" within comment .-Wcomment." }
+/* /* */  // { dg-warning "4: \"\.\*\" within comment .-Wcomment." }
 
 // \
-          // { dg-warning "multi-line comment .-Wcomment." "multi-line" { target *-*-* } 6 }
+          // { dg-warning "1: multi-line comment .-Wcomment." "multi-line" { target *-*-* } 6 }
diff --git a/libcpp/ChangeLog b/libcpp/ChangeLog
index 385b965488e..a5cef17df45 100644
--- a/libcpp/ChangeLog
+++ b/libcpp/ChangeLog
@@ -1,3 +1,12 @@
+2016-02-08  David Malcolm  <dmalcolm@redhat.com>
+
+	PR preprocessor/69664
+	* errors.c (cpp_diagnostic_with_line): Only call
+	rich_location::override_column if the column is non-zero.
+	* line-map.c (rich_location::override_column): Update columns
+	within m_ranges[0].  Add assertions to verify that doing so is
+	sane.
+
 2016-02-05  Jakub Jelinek  <jakub@redhat.com>
 
 	PR c++/69628
diff --git a/libcpp/errors.c b/libcpp/errors.c
index d92b38662ea..984737877be 100644
--- a/libcpp/errors.c
+++ b/libcpp/errors.c
@@ -141,7 +141,8 @@ cpp_diagnostic_with_line (cpp_reader * pfile, int level, int reason,
   if (!pfile->cb.error)
     abort ();
   rich_location richloc (pfile->line_table, src_loc);
-  richloc.override_column (column);
+  if (column)
+    richloc.override_column (column);
   ret = pfile->cb.error (pfile, level, reason, &richloc, _(msgid), ap);
 
   return ret;
diff --git a/libcpp/line-map.c b/libcpp/line-map.c
index fcf025956d1..e9175dfa307 100644
--- a/libcpp/line-map.c
+++ b/libcpp/line-map.c
@@ -2036,13 +2036,22 @@ rich_location::lazily_expand_location ()
   return m_expanded_location;
 }
 
-/* Set the column of the primary location.  */
+/* Set the column of the primary location.  This can only be called for
+   rich_location instances for which the primary location has
+   caret==start==finish.  */
 
 void
 rich_location::override_column (int column)
 {
   lazily_expand_location ();
+  gcc_assert (m_ranges[0].m_show_caret_p);
+  gcc_assert (m_ranges[0].m_caret.column == m_expanded_location.column);
+  gcc_assert (m_ranges[0].m_start.column == m_expanded_location.column);
+  gcc_assert (m_ranges[0].m_finish.column == m_expanded_location.column);
   m_expanded_location.column = column;
+  m_ranges[0].m_caret.column = column;
+  m_ranges[0].m_start.column = column;
+  m_ranges[0].m_finish.column = column;
 }
 
 /* Add the given range.  */