Fixed #10547 (False positive: constVariable, buffer written by stream read)

lib/checkother.cpp

@@ -1525,10 +1525,15 @@ void CheckOther::checkConstPointer()
             if (!p->scope() || !p->scope()->function || p->scope()->function->isImplicitlyVirtual(true) || p->scope()->function->hasVirtualSpecifier())
                 continue;
         }
-        if (nonConstPointers.find(p) == nonConstPointers.end())
+        if (nonConstPointers.find(p) == nonConstPointers.end()) {
+            const Token *start = (p->isArgument()) ? p->scope()->bodyStart : p->nameToken()->next();
+            const int indirect = p->isArray() ? p->dimensions().size() : 1;
+            if (isVariableChanged(start, p->scope()->bodyEnd, indirect, p->declarationId(), false, mSettings, mTokenizer->isCPP()))
+                continue;
             constVariableError(p, nullptr);
         }
     }
+}
 void CheckOther::constVariableError(const Variable *var, const Function *function)
 {
     const std::string vartype((var && var->isArgument()) ? "Parameter" : "Variable");

test/testother.cpp

@@ -2764,6 +2764,13 @@ private:
               "    memcpy(data.buf, &a, sizeof(a));\n"
               "}");
         ASSERT_EQUALS("", errout.str());
+
+        // #10547
+        check("void foo(std::istream &istr) {\n"
+              "  unsigned char x[2];\n"
+              "  istr >> x[0];\n"
+              "}");
+        ASSERT_EQUALS("", errout.str());
     }
 
     void switchRedundantAssignmentTest() {