From 55e2fe5d27f328b7afb207a561ee618052fad9ac Mon Sep 17 00:00:00 2001
From: Jean-Francois Dockes <jf@dockes.org>
Date: Thu, 15 Nov 2018 18:19:39 +0100
Subject: [PATCH] Prevent text splitter bad array access and stl assertion
 crash (fedora rpmbuild) in marginal case. There were probably no real
 consequence beyond triggering the assertion

---
 src/common/textsplit.cpp | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/src/common/textsplit.cpp b/src/common/textsplit.cpp
index c5b47d27..bd80f049 100644
--- a/src/common/textsplit.cpp
+++ b/src/common/textsplit.cpp
@@ -340,6 +340,15 @@ bool TextSplit::words_from_span(size_t bp)
     cerr << endl;
 #endif
     int spanwords = int(m_words_in_span.size());
+    // It seems that something like: tv_combo-sample_util.Po@am_quote
+    // can get the splitter to call doemit with a span of '@' and
+    // words_in_span==0, which then causes a crash when accessing
+    // words_in_span[0] if the stl assertions are active (e.g. Fedora
+    // RPM build). Not too sure what the right fix would be, but for
+    // now, just defend against it
+    if (spanwords == 0) {
+        return true;
+    }
     int pos = m_spanpos;
     // Byte position of the span start
     size_t spboffs = bp - m_span.size();