Fix ticket #302 (White space between "\" and newline not handled correctly)

http://apps.sourceforge.net/trac/cppcheck/ticket/302

src/preprocessor.cpp

@@ -159,7 +159,21 @@ std::string Preprocessor::read(std::istream &istr)
         // <backspace><newline>..
         else if (ch == '\\')
         {
-            char chNext = (char)istr.peek();
+            char chNext = 0;
+            while (true)
+            {
+                chNext = (char)istr.peek();
+                if (chNext != '\n' && chNext != '\r' &&
+                    (std::isspace(chNext) || std::iscntrl(chNext)))
+                {
+                    // Skip whitespace between <backspace> and <newline>
+                    (void)readChar(istr);
+                    continue;
+                }
+
+                break;
+            }
+
             if (chNext == '\n' || chNext == '\r')
             {
                 ++newlines;

test/testpreprocessor.cpp

@@ -86,6 +86,7 @@ private:
         TEST_CASE(multiline1);
         TEST_CASE(multiline2);
         TEST_CASE(multiline3);
+        TEST_CASE(multiline4);
 
         TEST_CASE(if_defined);      // "#if defined(AAA)" => "#ifdef AAA"
 
@@ -516,7 +517,24 @@ private:
         ASSERT_EQUALS("const char *str = \"abcdefghi\"\n\n\n", preprocessor.read(istr));
     }
 
+    void multiline4()
+    {
+        errout.str("");
+        const char filedata[] = "#define A int a = 4;\\ \n"
+                                " int b = 5;\n"
+                                "A\n";
 
+        // Preprocess => actual result..
+        std::istringstream istr(filedata);
+        std::map<std::string, std::string> actual;
+        Preprocessor preprocessor;
+        preprocessor.preprocess(istr, actual, "file.c");
+
+        // Compare results..
+        ASSERT_EQUALS(1, static_cast<unsigned int>(actual.size()));
+        ASSERT_EQUALS("\n\nint a = 4; int b = 5;\n", actual[""]);
+        ASSERT_EQUALS("", errout.str());
+    }
 
     void if_defined()
     {
@@ -892,6 +910,7 @@ private:
 
     void define_part_of_func()
     {
+        errout.str("");
         const char filedata[] = "#define A g(\n"
                                 "void f() {\n"
                                 "  A );\n"