Add tests for #6925, #11042, #11494 (#4987)

* Add tests for #6925, #11042, #11494

* Format

Author: chrchr-github

test/testbufferoverrun.cpp

@@ -5250,6 +5250,16 @@ class TestBufferOverrun : public TestFixture {
             "    g(a);\n"
             "}\n");
         ASSERT_EQUALS("", errout.str());
+
+        ctu("const int a[1] = { 1 };\n" // #11042
+            "void g(const int* d) {\n"
+            "    (void)d[2];\n"
+            "}\n"
+            "void f() {\n"
+            "    g(a);\n"
+            "}\n");
+        ASSERT_EQUALS("[test.cpp:6] -> [test.cpp:3]: (error) Array index out of bounds; 'd' buffer size is 4 and it is accessed at offset 8.\n",
+                      errout.str());
     }
 
     void ctu_variable() {

test/testsimplifytypedef.cpp

@@ -3213,8 +3213,8 @@ class TestSimplifyTypedef : public TestFixture {
             tok(code));
     }
 
-    void simplifyTypedef140() { // #10798
-        {
+    void simplifyTypedef140() {
+        { // #10798
             const char code[] = "typedef void (*b)();\n"
                                 "enum class E { a, b, c };\n";
             ASSERT_EQUALS("enum class E { a , b , c } ;", tok(code));
@@ -3224,6 +3224,11 @@ class TestSimplifyTypedef : public TestFixture {
                                 "enum class E { A };\n";
             ASSERT_EQUALS("enum class E { A } ;", tok(code));
         }
+        { // #11494
+            const char code[] = "typedef struct S {} KEY;\n"
+                                "class C { enum E { KEY }; };\n";
+            ASSERT_EQUALS("struct S { } ; class C { enum E { KEY } ; } ;", tok(code));
+        }
     }
 
     void simplifyTypedef141() { // #10144

test/teststl.cpp

@@ -4750,6 +4750,15 @@ class TestStl : public TestFixture {
               "    return true;\n"
               "}\n");
         ASSERT_EQUALS("", errout.str());
+
+        // #6925
+        check("void f(const std::string& s, std::string::iterator i) {\n"
+              "    if (i != s.end() && *(i + 1) == *i) {\n"
+              "        if (i + 1 != s.end()) {}\n"
+              "    }\n"
+              "}\n");
+        ASSERT_EQUALS("[test.cpp:3] -> [test.cpp:2]: (warning) Either the condition 'i+1!=s.end()' is redundant or there is possible dereference of an invalid iterator: i+1.\n",
+                      errout.str());
     }
 
     void dereferenceInvalidIterator2() {