common: Fix isChannelName crash on empty string

Add check to isChannelName for an empty string; return false if so
and don't try to index it.  This avoids crashing on connect for some
situations.

Closes GH-307.

diff --git a/src/common/util.cpp b/src/common/util.cpp
index 3d199a1..a59db8f 100644 (file)
--- a/src/common/util.cpp
+++ b/src/common/util.cpp
@@ -64,6 +64,8 @@ QString hostFromMask(const QString &mask)
 
 bool isChannelName(const QString &str)
 {
+    if (str.isEmpty())
+        return false;
     static constexpr std::array<quint8, 4> prefixes{{'#', '&', '!', '+'}};
     return std::any_of(prefixes.cbegin(), prefixes.cend(), [&str](quint8 c) { return c == str[0]; });
 }