diff --git a/lib/checkother.cpp b/lib/checkother.cpp
index cf448b273..e6667430c 100644
--- a/lib/checkother.cpp
+++ b/lib/checkother.cpp
@@ -903,6 +903,12 @@ static int doAssignment(Variables &variables, const Token *tok, bool dereference
                     next = start + 5 + offset;
             }
 
+            // check for var ? ...
+            else if (Token::Match(tok->tokAt(start), "%var% ?"))
+            {
+                next = start;
+            }
+
             // no cast
             else
             {
@@ -937,6 +943,13 @@ static int doAssignment(Variables &variables, const Token *tok, bool dereference
 
                             variables.alias(varid1, varid2, replace);
                         }
+                        else if (tok->tokAt(next + 1)->str() == "?")
+                        {
+                            if (var2->_type == Variables::reference)
+                                variables.readAliases(varid2);
+                            else
+                                variables.read(varid2);
+                        }
                     }
                 }
                 else if (var1->_type == Variables::reference)
diff --git a/test/testunusedvar.cpp b/test/testunusedvar.cpp
index 6d4bf252f..da4a1fc4b 100644
--- a/test/testunusedvar.cpp
+++ b/test/testunusedvar.cpp
@@ -70,6 +70,7 @@ private:
         TEST_CASE(localvar22); // ticket #1811
         TEST_CASE(localvar23); // ticket #1808
         TEST_CASE(localvar24); // ticket #1803
+        TEST_CASE(localvar25); // ticket #1729
         TEST_CASE(localvaralias1);
         TEST_CASE(localvaralias2); // ticket #1637
         TEST_CASE(localvaralias3); // ticket #1639
@@ -1232,6 +1233,18 @@ private:
         ASSERT_EQUALS("", errout.str());
     }
 
+    void localvar25() // ticket #1729
+    {
+        functionVariableUsage("int main() {\n"
+                              "    int ppos = 1;\n"
+                              "    int pneg = 0;\n"
+                              "    const char*edge = ppos? \" +\" : pneg ? \" -\" : \"\";\n"
+                              "    printf(\"This should be a '+' -> %s\n\", edge);\n"
+                              "    return 0;\n"
+                              "}\n");
+        ASSERT_EQUALS("", errout.str());
+    }
+
     void localvaralias1()
     {
         functionVariableUsage("void foo()\n"