libcutils: Use strnlen for default property values am: e67abec514 am: 6632536c0d am: f957e56909
am: 9bc7869b79

Change-Id: Iba1796493404418216f4f25078ddebac6e8034d5
diff --git a/libcutils/properties.c b/libcutils/properties.c
index 69c6c7f..740c7a9 100644
--- a/libcutils/properties.c
+++ b/libcutils/properties.c
@@ -119,10 +119,7 @@
         return len;
     }
     if (default_value) {
-        len = strlen(default_value);
-        if (len >= PROPERTY_VALUE_MAX) {
-            len = PROPERTY_VALUE_MAX - 1;
-        }
+        len = strnlen(default_value, PROPERTY_VALUE_MAX - 1);
         memcpy(value, default_value, len);
         value[len] = '\0';
     }
diff --git a/libcutils/tests/PropertiesTest.cpp b/libcutils/tests/PropertiesTest.cpp
index f0cdffd..7921972 100644
--- a/libcutils/tests/PropertiesTest.cpp
+++ b/libcutils/tests/PropertiesTest.cpp
@@ -159,19 +159,68 @@
 
 TEST_F(PropertiesTest, GetString) {
 
-    // Try to use a default value that's too long => set fails
+    // Try to use a default value that's too long => get truncates the value
     {
         ASSERT_OK(property_set(PROPERTY_TEST_KEY, ""));
 
-        std::string maxLengthString = std::string(PROPERTY_VALUE_MAX-1, 'a');
+        std::string maxLengthString = std::string(PROPERTY_VALUE_MAX - 1, 'a');
         std::string oneLongerString = std::string(PROPERTY_VALUE_MAX, 'a');
 
         // Expect that the value is truncated since it's too long (by 1)
         int len = property_get(PROPERTY_TEST_KEY, mValue, oneLongerString.c_str());
-        EXPECT_EQ(PROPERTY_VALUE_MAX-1, len);
+        EXPECT_EQ(PROPERTY_VALUE_MAX - 1, len);
         EXPECT_STREQ(maxLengthString.c_str(), mValue);
         ResetValue();
     }
+
+    // Try to use a default value that's the max length => get succeeds
+    {
+        ASSERT_OK(property_set(PROPERTY_TEST_KEY, ""));
+
+        std::string maxLengthString = std::string(PROPERTY_VALUE_MAX - 1, 'b');
+
+        // Expect that the value matches maxLengthString
+        int len = property_get(PROPERTY_TEST_KEY, mValue, maxLengthString.c_str());
+        EXPECT_EQ(PROPERTY_VALUE_MAX - 1, len);
+        EXPECT_STREQ(maxLengthString.c_str(), mValue);
+        ResetValue();
+    }
+
+    // Try to use a default value of length one => get succeeds
+    {
+        ASSERT_OK(property_set(PROPERTY_TEST_KEY, ""));
+
+        std::string oneCharString = std::string(1, 'c');
+
+        // Expect that the value matches oneCharString
+        int len = property_get(PROPERTY_TEST_KEY, mValue, oneCharString.c_str());
+        EXPECT_EQ(1, len);
+        EXPECT_STREQ(oneCharString.c_str(), mValue);
+        ResetValue();
+    }
+
+    // Try to use a default value of length zero => get succeeds
+    {
+        ASSERT_OK(property_set(PROPERTY_TEST_KEY, ""));
+
+        std::string zeroCharString = std::string(0, 'd');
+
+        // Expect that the value matches oneCharString
+        int len = property_get(PROPERTY_TEST_KEY, mValue, zeroCharString.c_str());
+        EXPECT_EQ(0, len);
+        EXPECT_STREQ(zeroCharString.c_str(), mValue);
+        ResetValue();
+    }
+
+    // Try to use a NULL default value => get returns 0
+    {
+        ASSERT_OK(property_set(PROPERTY_TEST_KEY, ""));
+
+        // Expect a return value of 0
+        int len = property_get(PROPERTY_TEST_KEY, mValue, NULL);
+        EXPECT_EQ(0, len);
+        ResetValue();
+    }
 }
 
 TEST_F(PropertiesTest, GetBool) {