fix the bug of strRepr. Now single quote is escaped correctly

src/core/threading.cpp

@@ -148,7 +148,7 @@ static void _thread_context_dump(int signum, siginfo_t* info, void* _context) {
     if (VERBOSITY() >= 2) {
         printf("in thread_context_dump, tid=%d\n", tid);
         printf("%p %p %p\n", context, &context, context->uc_mcontext.fpregs);
-        printf("old rip: 0x%lx\n", context->uc_mcontext.gregs[REG_RIP]);
+        printf("old rip: 0x%llx\n", context->uc_mcontext.gregs[REG_RIP]);
     }
 
     pushThreadState(tid, context);

src/runtime/str.cpp

@@ -237,10 +237,14 @@ extern "C" Box* strRepr(BoxedString* self) {
     std::ostringstream os("");
 
     const std::string& s = self->s;
-    os << '\'';
+    char quote = '\'';
+    if (s.find('\'', 0) != std::string::npos && s.find('\"', 0) == std::string::npos) {
+        quote = '\"';
+    }
+    os << quote;
     for (int i = 0; i < s.size(); i++) {
         char c = s[i];
-        if (!_needs_escaping[c & 0xff]) {
+        if ((c == '\'' && quote == '\"') || !_needs_escaping[c & 0xff]) {
             os << c;
         } else {
             char special = 0;
@@ -275,7 +279,7 @@ extern "C" Box* strRepr(BoxedString* self) {
             }
         }
     }
-    os << '\'';
+    os << quote;
 
     return boxString(os.str());
 }

test/tests/repr.py

+a=1
+try:
+    a.b
+except AttributeError, e:
+    print repr(e)
+
+print repr("both\'\"quotes")
+print repr("single\'quote")
+print repr("double\"quote")