From 79daad8ff4ecbbc5831c2616d9dc586cc5d51526 Mon Sep 17 00:00:00 2001
From: chrchr-github <78114321+chrchr-github@users.noreply.github.com>
Date: Thu, 1 Sep 2022 22:59:46 +0200
Subject: [PATCH] Fix #11020 FP arrayIndexOutOfBounds if string literals are
 assigned conditionally (#4428)

---
 lib/programmemory.cpp      | 2 +-
 test/testbufferoverrun.cpp | 9 +++++++++
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/lib/programmemory.cpp b/lib/programmemory.cpp
index 72d7c00d1..fbb00e496 100644
--- a/lib/programmemory.cpp
+++ b/lib/programmemory.cpp
@@ -1245,7 +1245,7 @@ static ValueFlow::Value executeImpl(const Token* expr, ProgramMemory& pm, const
             auto tokvalue_it = std::find_if(expr->astOperand1()->values().begin(),
                                             expr->astOperand1()->values().end(),
                                             std::mem_fn(&ValueFlow::Value::isTokValue));
-            if (tokvalue_it == expr->astOperand1()->values().end()) {
+            if (tokvalue_it == expr->astOperand1()->values().end() || !tokvalue_it->isKnown()) {
                 return unknown;
             }
             tokvalue = tokvalue_it->tokvalue;
diff --git a/test/testbufferoverrun.cpp b/test/testbufferoverrun.cpp
index 9aa5eea15..7bd86d11e 100644
--- a/test/testbufferoverrun.cpp
+++ b/test/testbufferoverrun.cpp
@@ -2524,6 +2524,15 @@ private:
               "    snprintf(str, sizeof(str), \"%hu\", port);\n"
               "}", settings0, "test.c");
         ASSERT_EQUALS("", errout.str());
+
+        check("int f(int x) {\n" // #11020
+              "    const char* p = (x == 0 ? \"12345\" : \"ABC\");\n"
+              "    int s = 0;\n"
+              "    for (int i = 0; p[i]; i++)\n"
+              "        s += p[i];\n"
+              "    return s;\n"
+              "}\n");
+        ASSERT_EQUALS("", errout.str());
     }
 
     void array_index_same_struct_and_var_name() {