Added further optimizations and unit tests.

test/val/lib_common_strncat.c

@@ -0,0 +1,54 @@
+#include <string.h>
+#include "unittest.h"
+
+#define SourceStringSize 384                            // test correct page passing (>256, multiple of 128 here)
+
+static char SourceString[SourceStringSize+1];           // +1 room for terminating null
+static char DestinationString[2*SourceStringSize+1];    // will contain two times the source buffer
+
+
+TEST
+{
+    unsigned i;
+    char*    p;
+    
+    for (i=0; i < SourceStringSize; ++i)
+      SourceString[i] = (i%128)+1;
+
+    SourceString[i] = 0;
+
+    ASSERT_AreEqual(SourceStringSize, strlen(SourceString), "%u", "Source string initialization or 'strlen()' problem!");
+
+    /* Ensure empty destination string */
+    DestinationString[0] = 0;
+
+    ASSERT_AreEqual(0, strlen(DestinationString), "%u", "Destination string initialization or 'strlen()' problem!");
+    
+    /* Test "unlimted" concatenation to empty buffer */
+
+    strncat(DestinationString, SourceString, 1024);
+    
+    ASSERT_AreEqual(SourceStringSize, strlen(DestinationString), "%u", "Unexpected string length while string concatenation to empty buffer!");
+    
+    /* Test limited concatenation to non empty buffer */
+
+    p = strncat(DestinationString, SourceString, 128);
+
+    ASSERT_AreEqual(SourceStringSize+128, strlen(DestinationString), "%u", "Unexpected string length while string concatenation to non-empty buffer!");
+
+    /* Test return value */
+
+    ASSERT_IsTrue(p == DestinationString, "Invalid return value!");
+
+    /* Test contents */
+
+    for(i=0; i < strlen(DestinationString); ++i)
+    {
+        unsigned current = DestinationString[i];
+        unsigned expected = (i%128)+1;
+        ASSERT_AreEqual(expected, current, "%u", "Unexpected destination buffer contents at position %u!\n" COMMA i);
+    }
+}
+ENDTEST
+
+