CPlusPlus: Fix lexer crash

At some point in the preprocessing stage, some tokens get "squeezed", so
their associated string no longer refers to the document content, but
only to their own symbol. However, there is at least one context that
operated under the assumption that the token's offset still pointed into
the "global" string. As the token's offset is zero after parsing, this
lead to the same piece of code being preprocessed in an infinite loop.

Fixes: QTCREATORBUG-19525
Change-Id: I231ba51811cfa0b5c6dfe7f75fe0384472252c6f
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

1 files changed, 1 insertions, 0 deletions

diff --git a/src/libs/cplusplus/PPToken.cpp b/src/libs/cplusplus/PPToken.cpp
index 2f352fa109..ff3996aba9 100644
--- a/src/libs/cplusplus/PPToken.cpp
+++ b/src/libs/cplusplus/PPToken.cpp
@@ -54,6 +54,7 @@ void PPToken::squeezeSource()
     if (hasSource()) {
         m_src = m_src.mid(byteOffset, f.bytes);
         m_src.squeeze();
+        m_originalOffset = byteOffset;
         byteOffset = 0;
         utf16charOffset = 0;
     }