C++: Fix maxCols.

Author: geoffw0

cpp/ql/src/semmle/code/cpp/Location.qll

@@ -128,7 +128,7 @@ deprecated library class LocationExpr extends Location, @location_expr { }
  * Gets the length of the longest line in file `f`.
  */
 pragma[nomagic]
-private int maxCols(File f) { result = max(Location l | l.getFile() = f | l.getEndColumn()) }
+private int maxCols(File f) { result = max(Location l | l.getFile() = f | [l.getStartColumn(), l.getEndColumn()]) }
 
 /**
  * A C/C++ element that has a location in a file

cpp/ql/test/library-tests/locations/charloc/charloc.expected

@@ -1,6 +1,6 @@
-| charloc.cpp | 1 | 39 | 39 | 1 |
-| charloc.cpp | 2 | 48 | 48 | 2 |
-| charloc.cpp | 3 | 52 | 52 | 3 |
-| charloc.cpp | 4 | 64 | 64 | 4 |
-| charloc.cpp | (...) | 65 | 65 | (...) |
-| charloc.cpp | ... + ... | 48 | 52 | ... + ..., 2, 3 |
+| charloc.cpp | 1 | 47 | 47 | 1 |
+| charloc.cpp | 2 | 58 | 58 | 2 |
+| charloc.cpp | 3 | 62 | 62 | 3 |
+| charloc.cpp | 4 | 78 | 78 | 4 |
+| charloc.cpp | (...) | 77 | 79 | (...), 4 |
+| charloc.cpp | ... + ... | 58 | 62 | ... + ..., 2, 3 |

cpp/ql/test/query-tests/definitions/locationInfo.ql

@@ -11,7 +11,7 @@ class Link extends Top {
  * Gets the length of the longest line in file `f`.
  */
 pragma[nomagic]
-private int maxCols(File f) { result = max(Location l | l.getFile() = f | l.getEndColumn()) }
+private int maxCols(File f) { result = max(Location l | l.getFile() = f | [l.getStartColumn(), l.getEndColumn()]) }
 
 /**
  * Gets the location of an element that has a link-to-definition (in a similar manner to