5402 false positive: (error) Division by zero -- with boost::format

lib/checkother.cpp

@@ -1797,10 +1797,20 @@ void CheckOther::checkZeroDivision()
     const bool printInconclusive = _settings->inconclusive;
 
     for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) {
-        if (!Token::Match(tok, "[/%]") || !tok->astOperand2())
+        if (!Token::Match(tok, "[/%]") || !tok->astOperand1() || !tok->astOperand2())
             continue;
         if (astIsFloat(tok,false))
             continue;
+        if (tok->astOperand1()->isNumber()) {
+            if (MathLib::isFloat(tok->astOperand1()->str()))
+                continue;
+        } else if (tok->astOperand1()->isName()) {
+            if (tok->astOperand1()->variable() && !tok->astOperand1()->variable()->isIntegralType())
+                continue;
+        } else {
+            continue;
+        }
+
         // Value flow..
         const ValueFlow::Value *value = tok->astOperand2()->getValue(0LL);
         if (!value)

test/testother.cpp

@@ -42,6 +42,7 @@ private:
         TEST_CASE(zeroDiv7);  // #4930
         TEST_CASE(zeroDiv8);
         TEST_CASE(zeroDiv9);
+        TEST_CASE(zeroDiv10);
 
         TEST_CASE(zeroDivCond); // division by zero / useless condition
 
@@ -376,6 +377,17 @@ private:
         ASSERT_EQUALS("", errout.str());
     }
 
+    void zeroDiv10() {
+        // #5402 false positive: (error) Division by zero -- with boost::format
+        check("int main() {\n"
+              "  std::cout\n"
+              "    << boost::format(\" %d :: %s <> %s\") % 0 % \"a\" % \"b\"\n"
+              "    << std::endl;\n"
+              "  return 0;\n"
+              "}");
+        ASSERT_EQUALS("", errout.str());
+    }
+
     void zeroDivCond() {
         check("void f(unsigned int x) {\n"
               "  int y = 17 / x;\n"