Fixes daniele77#47 (assertion in History::Next() when the buffer is empty)

Daniele Pallastrelli · Daniele Pallastrelli · commit 89c4437f94de · 2019-07-22T16:57:36.000+02:00
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -6,6 +6,7 @@ Current Version: 1.1-dirty
 
  - Specify binding IP address in CliTelnetServer (issue #44)
  - Fix compilation with boost v. 1.70.0 (issue #40)
+ - Fix assertion in History::Next() when buffer is empty (issue #47)
  - Fix compilation with older boost versions (< 1.66.0)
  - CMake generates cli.pc configuration file for pkg-config
 
diff --git a/include/cli/history.h b/include/cli/history.h
@@ -94,6 +94,8 @@ class History
     // Return the next item of the history, updating the current item.
     std::string Next()
     {
+        if (buffer.empty())
+            return {};
         if (current != 0)
             --current;
         assert(current < buffer.size());
diff --git a/test/test_history.cpp b/test/test_history.cpp
@@ -89,4 +89,17 @@ BOOST_AUTO_TEST_CASE(Insertion)
     BOOST_CHECK_EQUAL(history.Previous("foo"), "item2");
 }
 
+BOOST_AUTO_TEST_CASE(Empty)
+{
+    History history(10);
+
+    BOOST_CHECK_EQUAL(history.Next(), "");
+    BOOST_CHECK_EQUAL(history.Previous(""), "");
+
+    History history2(10);
+
+    BOOST_CHECK_EQUAL(history2.Previous(""), "");
+    BOOST_CHECK_EQUAL(history2.Next(), "");
+}
+
 BOOST_AUTO_TEST_SUITE_END()

Original file line number	Diff line number	Diff line change
`@@ -94,6 +94,8 @@ class History`
`94`	`94`	`// Return the next item of the history, updating the current item.`
`95`	`95`	`std::string Next()`
`96`	`96`	`{`
	`97`	`+ if (buffer.empty())`
	`98`	`+ return {};`
`97`	`99`	`if (current != 0)`
`98`	`100`	`--current;`
`99`	`101`	`assert(current < buffer.size());`