From ea81ce933ea989806335ceef148dcd717abb2aff Mon Sep 17 00:00:00 2001
From: chrchr-github <78114321+chrchr-github@users.noreply.github.com>
Date: Tue, 25 Jan 2022 12:13:49 +0100
Subject: [PATCH] Fix #10754 FP invalidFunctionArg with resize() (#3737)

---
 lib/checkfunctions.cpp |  2 +-
 test/testfunctions.cpp | 38 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 39 insertions(+), 1 deletion(-)

diff --git a/lib/checkfunctions.cpp b/lib/checkfunctions.cpp
index 87f200bdb..4ac614610 100644
--- a/lib/checkfunctions.cpp
+++ b/lib/checkfunctions.cpp
@@ -154,7 +154,7 @@ void CheckFunctions::invalidFunctionArgError(const Token *tok, const std::string
         errmsg << " The value is 0 or 1 (boolean) but the valid values are '" << validstr << "'.";
     if (invalidValue)
         reportError(getErrorPath(tok, invalidValue, "Invalid argument"),
-                    invalidValue->errorSeverity() ? Severity::error : Severity::warning,
+                    invalidValue->errorSeverity() && invalidValue->isKnown() ? Severity::error : Severity::warning,
                     "invalidFunctionArg",
                     errmsg.str(),
                     CWE628,
diff --git a/test/testfunctions.cpp b/test/testfunctions.cpp
index bc94487a4..05e16b6f8 100644
--- a/test/testfunctions.cpp
+++ b/test/testfunctions.cpp
@@ -464,6 +464,44 @@ private:
 
         check("void f() { strtol(a,b,10); }");
         ASSERT_EQUALS("", errout.str());
+
+        check("void f(std::vector<int>& v) {\n" //  #10754
+              "    int N = -1;\n"
+              "    for (long i = 0; i < g(); i++)\n"
+              "        N = h(N);\n"
+              "    v.resize(N);\n"
+              "}\n");
+        ASSERT_EQUALS("[test.cpp:5]: (warning) Invalid v.resize() argument nr 1. The value is -1 but the valid values are '0:'.\n", errout.str());
+
+        check("void f(std::vector<int>& v, int N) {\n"
+              "    if (N < -1)\n"
+              "        return;\n"
+              "    v.resize(N);\n"
+              "}\n");
+        ASSERT_EQUALS("[test.cpp:2] -> [test.cpp:4]: (warning) Either the condition 'N<-1' is redundant or v.resize() argument nr 1 can have invalid value. The value is -1 but the valid values are '0:'.\n",
+                      errout.str());
+
+        check("void f(std::vector<int>& v, int N) {\n"
+              "    if (N == -1) {}\n"
+              "    v.resize(N);\n"
+              "}\n");
+        ASSERT_EQUALS("[test.cpp:2] -> [test.cpp:3]: (warning) Either the condition 'N==-1' is redundant or v.resize() argument nr 1 can have invalid value. The value is -1 but the valid values are '0:'.\n",
+                      errout.str());
+
+        check("void f(std::vector<int>& v, int N, bool b) {\n"
+              "    if (b)\n"
+              "        N = -1;\n"
+              "    v.resize(N);\n"
+              "}\n");
+        ASSERT_EQUALS("[test.cpp:4]: (warning) Invalid v.resize() argument nr 1. The value is -1 but the valid values are '0:'.\n",
+                      errout.str());
+
+        check("void f(std::vector<int>& v) {\n"
+              "    int N = -1;\n"
+              "    v.resize(N);\n"
+              "}\n");
+        ASSERT_EQUALS("[test.cpp:3]: (error) Invalid v.resize() argument nr 1. The value is -1 but the valid values are '0:'.\n",
+                      errout.str());
     }
 
     void invalidFunctionUsageStrings() {