From f6399c4cba7a978ed26fbb75d13db061dcee462f Mon Sep 17 00:00:00 2001
From: Paul Fultz II <pfultz2@yahoo.com>
Date: Fri, 20 Nov 2020 02:36:09 -0600
Subject: [PATCH] Fix issue 9980: FP nullPointerRedundantCheck - condition
 after while loop (#2912)

---
 lib/reverseanalyzer.cpp  |  2 +-
 test/testnullpointer.cpp | 21 +++++++++++++++++++++
 2 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/lib/reverseanalyzer.cpp b/lib/reverseanalyzer.cpp
index f698dacee..a6a86f63e 100644
--- a/lib/reverseanalyzer.cpp
+++ b/lib/reverseanalyzer.cpp
@@ -173,7 +173,7 @@ struct ReverseTraversal {
                 if (!continueB)
                     break;
                 valueFlowGenericForward(assignTop->astOperand2(), analyzer, settings);
-                tok = previousBeforeAstLeftmostLeaf(assignTop);
+                tok = previousBeforeAstLeftmostLeaf(assignTop)->next();
                 continue;
             }
             if (tok->str() == "}") {
diff --git a/test/testnullpointer.cpp b/test/testnullpointer.cpp
index 86cbd1c93..94d772911 100644
--- a/test/testnullpointer.cpp
+++ b/test/testnullpointer.cpp
@@ -105,6 +105,7 @@ private:
         TEST_CASE(nullpointer62);
         TEST_CASE(nullpointer63);
         TEST_CASE(nullpointer64);
+        TEST_CASE(nullpointer65); // #9980
         TEST_CASE(nullpointer_addressOf); // address of
         TEST_CASE(nullpointerSwitch); // #2626
         TEST_CASE(nullpointer_cast); // #4692
@@ -2011,6 +2012,26 @@ private:
         ASSERT_EQUALS("", errout.str());
     }
 
+    void nullpointer65() {
+        check("struct A {\n"
+              "    double get();\n"
+              "};\n"
+              "double x;\n"
+              "double run(A** begin, A** end) {\n"
+              "    A* a = nullptr;\n"
+              "    while (begin != end) {\n"
+              "        a = *begin;\n"
+              "        x = a->get();\n"
+              "        ++begin;\n"
+              "    }\n"
+              "    x = 0;\n"
+              "    if (a)\n"
+              "        return a->get();\n"
+              "    return 0;\n"
+              "}\n");
+        ASSERT_EQUALS("", errout.str());
+    }
+
     void nullpointer_addressOf() { // address of
         check("void f() {\n"
               "  struct X *x = 0;\n"