fixed #14732 - fixed potential crash with incomplete preprocessor directive (cppcheck-opensource#8539)

Author: firewave

lib/preprocessor.cpp

@@ -469,6 +469,8 @@ static std::string readcondition(const simplecpp::Token *iftok, const std::set<s
             continue;
         }
         if (cond->str() == "==" || cond->str() == "<=" || cond->str() == ">=") {
+            if (!cond->next)
+                break;
             if (cond->next->number) {
                 const simplecpp::Token *dtok = cond->previous;
                 if (sameline(iftok,dtok) && dtok->name && defined.find(dtok->str()) == defined.end() && undefined.find(dtok->str()) == undefined.end())
@@ -477,6 +479,8 @@ static std::string readcondition(const simplecpp::Token *iftok, const std::set<s
             continue;
         }
         if (cond->op == '<' || cond->op == '>') {
+            if (!cond->next)
+                break;
             if (cond->next->number) {
                 const simplecpp::Token *dtok = cond->previous;
                 if (sameline(iftok,dtok) && dtok->name && defined.find(dtok->str()) == defined.end() && undefined.find(dtok->str()) == undefined.end()) {

test/cli/fuzz-crash/crash-41fefbc326c326d02c9e1fe315280ddd326e8a5b

@@ -0,0 +1 @@
+#if<

test/testpreprocessor.cpp

@@ -343,6 +343,8 @@ class TestPreprocessor : public TestFixture {
         TEST_CASE(getConfigsAndCodeIssue14317);
         TEST_CASE(getConfigsMostGeneralConfigIssue14317);
 
+        TEST_CASE(getConfigsInvalid); // #14732
+
         TEST_CASE(if_sizeof);
 
         TEST_CASE(invalid_ifs); // #5909
@@ -2715,6 +2717,33 @@ class TestPreprocessor : public TestFixture {
         ASSERT_EQUALS("\nX\nY=Y\nZ\n", getConfigsStr(filedata));
     }
 
+    void getConfigsInvalid() { // #14732
+        {
+            const char filedata[] = "#if<";
+            ASSERT_EQUALS("\n", getConfigsStr(filedata));
+        }
+        {
+            const char filedata[] = "#if>";
+            ASSERT_EQUALS("\n", getConfigsStr(filedata));
+        }
+        {
+            const char filedata[] = "#if==";
+            ASSERT_EQUALS("\n", getConfigsStr(filedata));
+        }
+        {
+            const char filedata[] = "#if<=";
+            ASSERT_EQUALS("\n", getConfigsStr(filedata));
+        }
+        {
+            const char filedata[] = "#if>=";
+            ASSERT_EQUALS("\n", getConfigsStr(filedata));
+        }
+        {
+            const char filedata[] = "#if!";
+            ASSERT_EQUALS("\n", getConfigsStr(filedata));
+        }
+    }
+
     void if_sizeof() { // #4071
         const char code[] = "#if sizeof(unsigned short) == 2\n"
                             "Fred & Wilma\n"