commit 40d45a7bb3bd07d50562a468f9c550f555eb2f8a
author Jan Niklas Hasse <jhasse@bixense.com> Wed Oct 30 15:43:49 2019 +0100
committer GitHub <noreply@github.com> Wed Oct 30 15:43:49 2019 +0100
tree 322fc5928c55e35975dc517cb27d544921feef0b
parent 97c5949ffeb4ec84cec1290c118cf34aa0e503e4
parent 04ce2ea7a2930b32655823d55a8ff9865a37d6c2

Merge pull request #1654 from BourgondAries/master

Ensure substring indexing never goes negative

src/util.cc

diff --git a/src/util.cc b/src/util.cc
index 666cf9d..70096cd 100644
--- a/src/util.cc
+++ b/src/util.cc
@@ -596,6 +596,12 @@
 #endif // _WIN32
 
 string ElideMiddle(const string& str, size_t width) {
+  switch (width) {
+      case 0: return "";
+      case 1: return ".";
+      case 2: return "..";
+      case 3: return "...";
+  }
   const int kMargin = 3;  // Space for "...".
   string result = str;
   if (result.size() > width) {

src/util_test.cc

diff --git a/src/util_test.cc b/src/util_test.cc
index d97b48c..b43788d 100644
--- a/src/util_test.cc
+++ b/src/util_test.cc
@@ -420,6 +420,10 @@
   string input = "Nothing to elide in this short string.";
   EXPECT_EQ(input, ElideMiddle(input, 80));
   EXPECT_EQ(input, ElideMiddle(input, 38));
+  EXPECT_EQ("", ElideMiddle(input, 0));
+  EXPECT_EQ(".", ElideMiddle(input, 1));
+  EXPECT_EQ("..", ElideMiddle(input, 2));
+  EXPECT_EQ("...", ElideMiddle(input, 3));
 }
 
 TEST(ElideMiddle, ElideInTheMiddle) {