Fix subcase reentry (#598)

* Add tests

* Fix #597

* Slightly alternate approach to subcases

* Replace usage of non-standard contains method

* Merge branch 'dev' into fix-subcase-reentry

14 files changed, 664 insertions, 140 deletions

diff --git a/doctest/doctest.h b/doctest/doctest.h
index d576bbd5..efe5877f 100644
--- a/doctest/doctest.h
+++ b/doctest/doctest.h
@@ -807,6 +807,7 @@ struct DOCTEST_INTERFACE SubcaseSignature
     const char* m_file;
     int         m_line;
 
+    bool operator==(const SubcaseSignature& other) const;
     bool operator<(const SubcaseSignature& other) const;
 };
 
@@ -1230,6 +1231,9 @@ namespace detail {
         ~Subcase();
 
         operator bool() const;
+
+        private:
+            bool checkFilters();
     };
 
     template <typename L, typename R>
@@ -3105,6 +3109,7 @@ DOCTEST_MAKE_STD_HEADERS_CLEAN_FROM_WARNINGS_ON_WALL_BEGIN
 #endif // DOCTEST_CONFIG_NO_MULTITHREADING
 #include <set>
 #include <map>
+#include <unordered_set>
 #include <exception>
 #include <stdexcept>
 #include <csignal>
@@ -3469,11 +3474,12 @@ typedef timer_large_integer::type ticks_t;
         std::vector<String> stringifiedContexts; // logging from INFO() due to an exception
 
         // stuff for subcases
-        std::vector<SubcaseSignature>     subcasesStack;
-        std::set<decltype(subcasesStack)> subcasesPassed;
-        int                               subcasesCurrentMaxLevel;
-        bool                              should_reenter;
-        Atomic<bool>                      shouldLogCurrentException;
+        bool reachedLeaf;
+        std::vector<SubcaseSignature> subcaseStack;
+        std::vector<SubcaseSignature> nextSubcaseStack;
+        std::unordered_set<unsigned long long> fullyTraversedSubcases;
+        size_t currentSubcaseDepth;
+        Atomic<bool> shouldLogCurrentException;
 
         void resetRunData() {
             numTestCases                = 0;
@@ -3810,6 +3816,12 @@ const char* skipPathFromFilename(const char* file) {
 DOCTEST_CLANG_SUPPRESS_WARNING_POP
 DOCTEST_GCC_SUPPRESS_WARNING_POP
 
+bool SubcaseSignature::operator==(const SubcaseSignature& other) const {
+    return m_line == other.m_line
+        && std::strcmp(m_file, other.m_file) == 0
+        && m_name == other.m_name;
+}
+
 bool SubcaseSignature::operator<(const SubcaseSignature& other) const {
     if(m_line != other.m_line)
         return m_line < other.m_line;
@@ -4048,59 +4060,92 @@ namespace {
         return !*wild;
     }
 
-    //// C string hash function (djb2) - taken from http://www.cse.yorku.ca/~oz/hash.html
-    //unsigned hashStr(unsigned const char* str) {
-    //    unsigned long hash = 5381;
-    //    char          c;
-    //    while((c = *str++))
-    //        hash = ((hash << 5) + hash) + c; // hash * 33 + c
-    //    return hash;
-    //}
-
     // checks if the name matches any of the filters (and can be configured what to do when empty)
     bool matchesAny(const char* name, const std::vector<String>& filters, bool matchEmpty,
-                    bool caseSensitive) {
-        if(filters.empty() && matchEmpty)
+        bool caseSensitive) {
+        if (filters.empty() && matchEmpty)
             return true;
-        for(auto& curr : filters)
-            if(wildcmp(name, curr.c_str(), caseSensitive))
+        for (auto& curr : filters)
+            if (wildcmp(name, curr.c_str(), caseSensitive))
                 return true;
         return false;
     }
-} // namespace
-namespace detail {
 
-    Subcase::Subcase(const String& name, const char* file, int line)
-            : m_signature({name, file, line}) {
-        auto* s = g_cs;
+    unsigned long long hash(unsigned long long a, unsigned long long b) {
+        return (a << 5) + b;
+    }
 
-        // check subcase filters
-        if(s->subcasesStack.size() < size_t(s->subcase_filter_levels)) {
-            if(!matchesAny(m_signature.m_name.c_str(), s->filters[6], true, s->case_sensitive))
-                return;
-            if(matchesAny(m_signature.m_name.c_str(), s->filters[7], false, s->case_sensitive))
-                return;
-        }
-        
-        // if a Subcase on the same level has already been entered
-        if(s->subcasesStack.size() < size_t(s->subcasesCurrentMaxLevel)) {
-            s->should_reenter = true;
-            return;
-        }
+    // C string hash function (djb2) - taken from http://www.cse.yorku.ca/~oz/hash.html
+    unsigned long long hash(const char* str) {
+        unsigned long long hash = 5381;
+        char c;
+        while ((c = *str++))
+            hash = ((hash << 5) + hash) + c; // hash * 33 + c
+        return hash;
+    }
 
-        // push the current signature to the stack so we can check if the
-        // current stack + the current new subcase have been traversed
-        s->subcasesStack.push_back(m_signature);
-        if(s->subcasesPassed.count(s->subcasesStack) != 0) {
-            // pop - revert to previous stack since we've already passed this
-            s->subcasesStack.pop_back();
-            return;
+    unsigned long long hash(const SubcaseSignature& sig) {
+        return hash(hash(hash(sig.m_file), hash(sig.m_name.c_str())), sig.m_line);
+    }
+
+    unsigned long long hash(const std::vector<SubcaseSignature>& sigs, size_t count) {
+        unsigned long long running = 0;
+        auto end = sigs.begin() + count;
+        for (auto it = sigs.begin(); it != end; it++) {
+            running = hash(running, hash(*it));
         }
+        return running;
+    }
 
-        s->subcasesCurrentMaxLevel = s->subcasesStack.size();
-        m_entered = true;
+    unsigned long long hash(const std::vector<SubcaseSignature>& sigs) {
+        unsigned long long running = 0;
+        for (const SubcaseSignature& sig : sigs) {
+            running = hash(running, hash(sig));
+        }
+        return running;
+    }
+} // namespace
+namespace detail {
+    bool Subcase::checkFilters() {
+        if (g_cs->subcaseStack.size() < size_t(g_cs->subcase_filter_levels)) {
+            if (!matchesAny(m_signature.m_name.c_str(), g_cs->filters[6], true, g_cs->case_sensitive))
+                return true;
+            if (matchesAny(m_signature.m_name.c_str(), g_cs->filters[7], false, g_cs->case_sensitive))
+                return true;
+        }
+        return false;
+    }
 
-        DOCTEST_ITERATE_THROUGH_REPORTERS(subcase_start, m_signature);
+    Subcase::Subcase(const String& name, const char* file, int line)
+            : m_signature({name, file, line}) {
+        if (!g_cs->reachedLeaf) {
+            if (g_cs->nextSubcaseStack.size() <= g_cs->subcaseStack.size()
+                || g_cs->nextSubcaseStack[g_cs->subcaseStack.size()] == m_signature) {
+                // Going down.
+                if (checkFilters()) { return; }
+
+                g_cs->subcaseStack.push_back(m_signature);
+                g_cs->currentSubcaseDepth++;
+                m_entered = true;
+                DOCTEST_ITERATE_THROUGH_REPORTERS(subcase_start, m_signature);
+            }
+        } else {
+            if (g_cs->subcaseStack[g_cs->currentSubcaseDepth] == m_signature) {
+                // This subcase is reentered via control flow.
+                g_cs->currentSubcaseDepth++;
+                m_entered = true;
+                DOCTEST_ITERATE_THROUGH_REPORTERS(subcase_start, m_signature);
+            } else if (g_cs->nextSubcaseStack.size() <= g_cs->currentSubcaseDepth
+                    && g_cs->fullyTraversedSubcases.find(hash(hash(g_cs->subcaseStack, g_cs->currentSubcaseDepth), hash(m_signature)))
+                    == g_cs->fullyTraversedSubcases.end()) {
+                if (checkFilters()) { return; }
+                // This subcase is part of the one to be executed next.
+                g_cs->nextSubcaseStack.clear();
+                g_cs->nextSubcaseStack.insert(g_cs->nextSubcaseStack.end(),
+                    g_cs->subcaseStack.begin(), g_cs->subcaseStack.begin() + g_cs->currentSubcaseDepth);
+                g_cs->nextSubcaseStack.push_back(m_signature);
+            }
+        }
     }
 
     DOCTEST_MSVC_SUPPRESS_WARNING_WITH_PUSH(4996) // std::uncaught_exception is deprecated in C++17
@@ -4108,25 +4153,33 @@ namespace detail {
     DOCTEST_CLANG_SUPPRESS_WARNING_WITH_PUSH("-Wdeprecated-declarations")
 
     Subcase::~Subcase() {
-        if(m_entered) {
-            // only mark the subcase stack as passed if no subcases have been skipped
-            if(g_cs->should_reenter == false)
-                g_cs->subcasesPassed.insert(g_cs->subcasesStack);
-            g_cs->subcasesStack.pop_back();
+        if (m_entered) {
+            g_cs->currentSubcaseDepth--;
+
+            if (!g_cs->reachedLeaf) {
+                // Leaf.
+                g_cs->fullyTraversedSubcases.insert(hash(g_cs->subcaseStack));
+                g_cs->nextSubcaseStack.clear();
+                g_cs->reachedLeaf = true;
+            } else if (g_cs->nextSubcaseStack.empty()) {
+                // All children are finished.
+                g_cs->fullyTraversedSubcases.insert(hash(g_cs->subcaseStack));
+            }
 
 #if defined(__cpp_lib_uncaught_exceptions) && __cpp_lib_uncaught_exceptions >= 201411L && (!defined(__MAC_OS_X_VERSION_MIN_REQUIRED) || __MAC_OS_X_VERSION_MIN_REQUIRED >= 101200)
             if(std::uncaught_exceptions() > 0
 #else
             if(std::uncaught_exception()
 #endif
-            && g_cs->shouldLogCurrentException) {
+                && g_cs->shouldLogCurrentException) {
                 DOCTEST_ITERATE_THROUGH_REPORTERS(
                         test_case_exception, {"exception thrown in subcase - will translate later "
-                                              "when the whole test case has been exited (cannot "
-                                              "translate while there is an active exception)",
-                                              false});
+                                                "when the whole test case has been exited (cannot "
+                                                "translate while there is an active exception)",
+                                                false});
                 g_cs->shouldLogCurrentException = false;
             }
+
             DOCTEST_ITERATE_THROUGH_REPORTERS(subcase_end, DOCTEST_EMPTY);
         }
     }
@@ -4767,8 +4820,8 @@ namespace {
 
         DOCTEST_ITERATE_THROUGH_REPORTERS(test_case_exception, {message.c_str(), true});
 
-        while(g_cs->subcasesStack.size()) {
-            g_cs->subcasesStack.pop_back();
+        while (g_cs->subcaseStack.size()) {
+            g_cs->subcaseStack.pop_back();
             DOCTEST_ITERATE_THROUGH_REPORTERS(subcase_end, DOCTEST_EMPTY);
         }
 
@@ -6839,7 +6892,7 @@ int Context::run() {
             p->numAssertsFailedCurrentTest_atomic = 0;
             p->numAssertsCurrentTest_atomic       = 0;
 
-            p->subcasesPassed.clear();
+            p->fullyTraversedSubcases.clear();
 
             DOCTEST_ITERATE_THROUGH_REPORTERS(test_case_start, tc);
 
@@ -6849,9 +6902,10 @@ int Context::run() {
 
             do {
                 // reset some of the fields for subcases (except for the set of fully passed ones)
-                p->should_reenter          = false;
-                p->subcasesCurrentMaxLevel = 0;
-                p->subcasesStack.clear();
+                p->reachedLeaf = false;
+                // May not be empty if previous subcase exited via exception.
+                p->subcaseStack.clear();
+                p->currentSubcaseDepth = 0;
 
                 p->shouldLogCurrentException = true;
 
@@ -6885,9 +6939,9 @@ DOCTEST_MSVC_SUPPRESS_WARNING_POP
                     p->failure_flags |= TestCaseFailureReason::TooManyFailedAsserts;
                 }
                 
-                if(p->should_reenter && run_test)
+                if(!p->nextSubcaseStack.empty() && run_test)
                     DOCTEST_ITERATE_THROUGH_REPORTERS(test_case_reenter, tc);
-                if(!p->should_reenter)
+                if(p->nextSubcaseStack.empty())
                     run_test = false;
             } while(run_test);
 
diff --git a/doctest/parts/doctest.cpp b/doctest/parts/doctest.cpp
index bf9e1816..5d27a041 100644
--- a/doctest/parts/doctest.cpp
+++ b/doctest/parts/doctest.cpp
@@ -88,6 +88,7 @@ DOCTEST_MAKE_STD_HEADERS_CLEAN_FROM_WARNINGS_ON_WALL_BEGIN
 #endif // DOCTEST_CONFIG_NO_MULTITHREADING
 #include <set>
 #include <map>
+#include <unordered_set>
 #include <exception>
 #include <stdexcept>
 #include <csignal>
@@ -452,11 +453,12 @@ typedef timer_large_integer::type ticks_t;
         std::vector<String> stringifiedContexts; // logging from INFO() due to an exception
 
         // stuff for subcases
-        std::vector<SubcaseSignature>     subcasesStack;
-        std::set<decltype(subcasesStack)> subcasesPassed;
-        int                               subcasesCurrentMaxLevel;
-        bool                              should_reenter;
-        Atomic<bool>                      shouldLogCurrentException;
+        bool reachedLeaf;
+        std::vector<SubcaseSignature> subcaseStack;
+        std::vector<SubcaseSignature> nextSubcaseStack;
+        std::unordered_set<unsigned long long> fullyTraversedSubcases;
+        size_t currentSubcaseDepth;
+        Atomic<bool> shouldLogCurrentException;
 
         void resetRunData() {
             numTestCases                = 0;
@@ -793,6 +795,12 @@ const char* skipPathFromFilename(const char* file) {
 DOCTEST_CLANG_SUPPRESS_WARNING_POP
 DOCTEST_GCC_SUPPRESS_WARNING_POP
 
+bool SubcaseSignature::operator==(const SubcaseSignature& other) const {
+    return m_line == other.m_line
+        && std::strcmp(m_file, other.m_file) == 0
+        && m_name == other.m_name;
+}
+
 bool SubcaseSignature::operator<(const SubcaseSignature& other) const {
     if(m_line != other.m_line)
         return m_line < other.m_line;
@@ -1031,59 +1039,92 @@ namespace {
         return !*wild;
     }
 
-    //// C string hash function (djb2) - taken from http://www.cse.yorku.ca/~oz/hash.html
-    //unsigned hashStr(unsigned const char* str) {
-    //    unsigned long hash = 5381;
-    //    char          c;
-    //    while((c = *str++))
-    //        hash = ((hash << 5) + hash) + c; // hash * 33 + c
-    //    return hash;
-    //}
-
     // checks if the name matches any of the filters (and can be configured what to do when empty)
     bool matchesAny(const char* name, const std::vector<String>& filters, bool matchEmpty,
-                    bool caseSensitive) {
-        if(filters.empty() && matchEmpty)
+        bool caseSensitive) {
+        if (filters.empty() && matchEmpty)
             return true;
-        for(auto& curr : filters)
-            if(wildcmp(name, curr.c_str(), caseSensitive))
+        for (auto& curr : filters)
+            if (wildcmp(name, curr.c_str(), caseSensitive))
                 return true;
         return false;
     }
-} // namespace
-namespace detail {
 
-    Subcase::Subcase(const String& name, const char* file, int line)
-            : m_signature({name, file, line}) {
-        auto* s = g_cs;
+    unsigned long long hash(unsigned long long a, unsigned long long b) {
+        return (a << 5) + b;
+    }
 
-        // check subcase filters
-        if(s->subcasesStack.size() < size_t(s->subcase_filter_levels)) {
-            if(!matchesAny(m_signature.m_name.c_str(), s->filters[6], true, s->case_sensitive))
-                return;
-            if(matchesAny(m_signature.m_name.c_str(), s->filters[7], false, s->case_sensitive))
-                return;
-        }
-        
-        // if a Subcase on the same level has already been entered
-        if(s->subcasesStack.size() < size_t(s->subcasesCurrentMaxLevel)) {
-            s->should_reenter = true;
-            return;
-        }
+    // C string hash function (djb2) - taken from http://www.cse.yorku.ca/~oz/hash.html
+    unsigned long long hash(const char* str) {
+        unsigned long long hash = 5381;
+        char c;
+        while ((c = *str++))
+            hash = ((hash << 5) + hash) + c; // hash * 33 + c
+        return hash;
+    }
 
-        // push the current signature to the stack so we can check if the
-        // current stack + the current new subcase have been traversed
-        s->subcasesStack.push_back(m_signature);
-        if(s->subcasesPassed.count(s->subcasesStack) != 0) {
-            // pop - revert to previous stack since we've already passed this
-            s->subcasesStack.pop_back();
-            return;
+    unsigned long long hash(const SubcaseSignature& sig) {
+        return hash(hash(hash(sig.m_file), hash(sig.m_name.c_str())), sig.m_line);
+    }
+
+    unsigned long long hash(const std::vector<SubcaseSignature>& sigs, size_t count) {
+        unsigned long long running = 0;
+        auto end = sigs.begin() + count;
+        for (auto it = sigs.begin(); it != end; it++) {
+            running = hash(running, hash(*it));
         }
+        return running;
+    }
 
-        s->subcasesCurrentMaxLevel = s->subcasesStack.size();
-        m_entered = true;
+    unsigned long long hash(const std::vector<SubcaseSignature>& sigs) {
+        unsigned long long running = 0;
+        for (const SubcaseSignature& sig : sigs) {
+            running = hash(running, hash(sig));
+        }
+        return running;
+    }
+} // namespace
+namespace detail {
+    bool Subcase::checkFilters() {
+        if (g_cs->subcaseStack.size() < size_t(g_cs->subcase_filter_levels)) {
+            if (!matchesAny(m_signature.m_name.c_str(), g_cs->filters[6], true, g_cs->case_sensitive))
+                return true;
+            if (matchesAny(m_signature.m_name.c_str(), g_cs->filters[7], false, g_cs->case_sensitive))
+                return true;
+        }
+        return false;
+    }
 
-        DOCTEST_ITERATE_THROUGH_REPORTERS(subcase_start, m_signature);
+    Subcase::Subcase(const String& name, const char* file, int line)
+            : m_signature({name, file, line}) {
+        if (!g_cs->reachedLeaf) {
+            if (g_cs->nextSubcaseStack.size() <= g_cs->subcaseStack.size()
+                || g_cs->nextSubcaseStack[g_cs->subcaseStack.size()] == m_signature) {
+                // Going down.
+                if (checkFilters()) { return; }
+
+                g_cs->subcaseStack.push_back(m_signature);
+                g_cs->currentSubcaseDepth++;
+                m_entered = true;
+                DOCTEST_ITERATE_THROUGH_REPORTERS(subcase_start, m_signature);
+            }
+        } else {
+            if (g_cs->subcaseStack[g_cs->currentSubcaseDepth] == m_signature) {
+                // This subcase is reentered via control flow.
+                g_cs->currentSubcaseDepth++;
+                m_entered = true;
+                DOCTEST_ITERATE_THROUGH_REPORTERS(subcase_start, m_signature);
+            } else if (g_cs->nextSubcaseStack.size() <= g_cs->currentSubcaseDepth
+                    && g_cs->fullyTraversedSubcases.find(hash(hash(g_cs->subcaseStack, g_cs->currentSubcaseDepth), hash(m_signature)))
+                    == g_cs->fullyTraversedSubcases.end()) {
+                if (checkFilters()) { return; }
+                // This subcase is part of the one to be executed next.
+                g_cs->nextSubcaseStack.clear();
+                g_cs->nextSubcaseStack.insert(g_cs->nextSubcaseStack.end(),
+                    g_cs->subcaseStack.begin(), g_cs->subcaseStack.begin() + g_cs->currentSubcaseDepth);
+                g_cs->nextSubcaseStack.push_back(m_signature);
+            }
+        }
     }
 
     DOCTEST_MSVC_SUPPRESS_WARNING_WITH_PUSH(4996) // std::uncaught_exception is deprecated in C++17
@@ -1091,25 +1132,33 @@ namespace detail {
     DOCTEST_CLANG_SUPPRESS_WARNING_WITH_PUSH("-Wdeprecated-declarations")
 
     Subcase::~Subcase() {
-        if(m_entered) {
-            // only mark the subcase stack as passed if no subcases have been skipped
-            if(g_cs->should_reenter == false)
-                g_cs->subcasesPassed.insert(g_cs->subcasesStack);
-            g_cs->subcasesStack.pop_back();
+        if (m_entered) {
+            g_cs->currentSubcaseDepth--;
+
+            if (!g_cs->reachedLeaf) {
+                // Leaf.
+                g_cs->fullyTraversedSubcases.insert(hash(g_cs->subcaseStack));
+                g_cs->nextSubcaseStack.clear();
+                g_cs->reachedLeaf = true;
+            } else if (g_cs->nextSubcaseStack.empty()) {
+                // All children are finished.
+                g_cs->fullyTraversedSubcases.insert(hash(g_cs->subcaseStack));
+            }
 
 #if defined(__cpp_lib_uncaught_exceptions) && __cpp_lib_uncaught_exceptions >= 201411L && (!defined(__MAC_OS_X_VERSION_MIN_REQUIRED) || __MAC_OS_X_VERSION_MIN_REQUIRED >= 101200)
             if(std::uncaught_exceptions() > 0
 #else
             if(std::uncaught_exception()
 #endif
-            && g_cs->shouldLogCurrentException) {
+                && g_cs->shouldLogCurrentException) {
                 DOCTEST_ITERATE_THROUGH_REPORTERS(
                         test_case_exception, {"exception thrown in subcase - will translate later "
-                                              "when the whole test case has been exited (cannot "
-                                              "translate while there is an active exception)",
-                                              false});
+                                                "when the whole test case has been exited (cannot "
+                                                "translate while there is an active exception)",
+                                                false});
                 g_cs->shouldLogCurrentException = false;
             }
+
             DOCTEST_ITERATE_THROUGH_REPORTERS(subcase_end, DOCTEST_EMPTY);
         }
     }
@@ -1750,8 +1799,8 @@ namespace {
 
         DOCTEST_ITERATE_THROUGH_REPORTERS(test_case_exception, {message.c_str(), true});
 
-        while(g_cs->subcasesStack.size()) {
-            g_cs->subcasesStack.pop_back();
+        while (g_cs->subcaseStack.size()) {
+            g_cs->subcaseStack.pop_back();
             DOCTEST_ITERATE_THROUGH_REPORTERS(subcase_end, DOCTEST_EMPTY);
         }
 
@@ -3822,7 +3871,7 @@ int Context::run() {
             p->numAssertsFailedCurrentTest_atomic = 0;
             p->numAssertsCurrentTest_atomic       = 0;
 
-            p->subcasesPassed.clear();
+            p->fullyTraversedSubcases.clear();
 
             DOCTEST_ITERATE_THROUGH_REPORTERS(test_case_start, tc);
 
@@ -3832,9 +3881,10 @@ int Context::run() {
 
             do {
                 // reset some of the fields for subcases (except for the set of fully passed ones)
-                p->should_reenter          = false;
-                p->subcasesCurrentMaxLevel = 0;
-                p->subcasesStack.clear();
+                p->reachedLeaf = false;
+                // May not be empty if previous subcase exited via exception.
+                p->subcaseStack.clear();
+                p->currentSubcaseDepth = 0;
 
                 p->shouldLogCurrentException = true;
 
@@ -3868,9 +3918,9 @@ DOCTEST_MSVC_SUPPRESS_WARNING_POP
                     p->failure_flags |= TestCaseFailureReason::TooManyFailedAsserts;
                 }
                 
-                if(p->should_reenter && run_test)
+                if(!p->nextSubcaseStack.empty() && run_test)
                     DOCTEST_ITERATE_THROUGH_REPORTERS(test_case_reenter, tc);
-                if(!p->should_reenter)
+                if(p->nextSubcaseStack.empty())
                     run_test = false;
             } while(run_test);
 
diff --git a/doctest/parts/doctest_fwd.h b/doctest/parts/doctest_fwd.h
index 03162150..877b24c2 100644
--- a/doctest/parts/doctest_fwd.h
+++ b/doctest/parts/doctest_fwd.h
@@ -804,6 +804,7 @@ struct DOCTEST_INTERFACE SubcaseSignature
     const char* m_file;
     int         m_line;
 
+    bool operator==(const SubcaseSignature& other) const;
     bool operator<(const SubcaseSignature& other) const;
 };
 
@@ -1227,6 +1228,9 @@ namespace detail {
         ~Subcase();
 
         operator bool() const;
+
+        private:
+            bool checkFilters();
     };
 
     template <typename L, typename R>
diff --git a/examples/all_features/subcases.cpp b/examples/all_features/subcases.cpp
index df42b9d0..3fad25fd 100644
--- a/examples/all_features/subcases.cpp
+++ b/examples/all_features/subcases.cpp
@@ -34,6 +34,26 @@ TEST_CASE("lots of nested subcases") {
     }
 }
 
+TEST_CASE("reentering subcase via regular control flow") {
+    cout << endl << "root" << endl;
+    for (int i : { 0, 1, 2 }) {
+        cout << "outside of subcase" << endl;
+        SUBCASE("") { cout << "inside subcase " << i << endl; }
+        SUBCASE("") { cout << "also inside " << i << endl; }
+        SUBCASE("") {
+            if (i != 0) { FAIL(i); }
+            cout << "fail inside " << i << endl;
+        }
+        SUBCASE("") {
+            cout << "inside outside" << endl;
+            for (int j : { 0, 1, 2 }) {
+                SUBCASE("") { cout << "nested twice " << i << ", " << j << endl; }
+                SUBCASE("") { cout << "also twice " << i << ", " << j << endl; }
+            }
+        }
+    }
+}
+
 static void call_func() {
     SUBCASE("from function...") {
         MESSAGE("print me twice");
diff --git a/examples/all_features/test_output/filter_2.txt b/examples/all_features/test_output/filter_2.txt
index c734cf8f..9c154add 100644
--- a/examples/all_features/test_output/filter_2.txt
+++ b/examples/all_features/test_output/filter_2.txt
@@ -1,6 +1,6 @@
 [doctest] run with "--help" for options
 ===============================================================================
-[doctest] test cases: 0 | 0 passed | 0 failed | 99 skipped
+[doctest] test cases: 0 | 0 passed | 0 failed | 100 skipped
 [doctest] assertions: 0 | 0 passed | 0 failed |
 [doctest] Status: SUCCESS!
 Program code.
diff --git a/examples/all_features/test_output/filter_2_xml.txt b/examples/all_features/test_output/filter_2_xml.txt
index e36071cd..fa6cd147 100644
--- a/examples/all_features/test_output/filter_2_xml.txt
+++ b/examples/all_features/test_output/filter_2_xml.txt
@@ -104,6 +104,7 @@
     <TestCase name="part of some TS" filename="test_cases_and_suites.cpp" line="0" skipped="true"/>
   </TestSuite>
   <TestSuite>
+    <TestCase name="reentering subcase via regular control flow" filename="subcases.cpp" line="0" skipped="true"/>
     <TestCase name="should fail and no output" filename="no_failures.cpp" line="0" should_fail="true" skipped="true"/>
     <TestCase name="should fail and no output" filename="test_cases_and_suites.cpp" line="0" should_fail="true" skipped="true"/>
     <TestCase name="should fail because of an exception" filename="test_cases_and_suites.cpp" line="0" skipped="true"/>
@@ -141,6 +142,6 @@
     <TestCase name="without a funny name:" filename="subcases.cpp" line="0" skipped="true"/>
   </TestSuite>
   <OverallResultsAsserts successes="0" failures="0"/>
-  <OverallResultsTestCases successes="0" failures="0" skipped="99"/>
+  <OverallResultsTestCases successes="0" failures="0" skipped="100"/>
 </doctest>
 Program code.
diff --git a/examples/all_features/test_output/filter_3.txt b/examples/all_features/test_output/filter_3.txt
index e2f2be93..7da4b5c4 100644
--- a/examples/all_features/test_output/filter_3.txt
+++ b/examples/all_features/test_output/filter_3.txt
@@ -1,6 +1,11 @@
 [doctest] run with "--help" for options
 
 root
+
+root
+outside of subcase
+outside of subcase
+outside of subcase
 ===============================================================================
 subcases.cpp(0):
 TEST CASE:  subcases can be used in a separate function as well
@@ -34,7 +39,7 @@ TEST CASE:  without a funny name:
 subcases.cpp(0): MESSAGE: Nooo
 
 ===============================================================================
-[doctest] test cases: 9 | 9 passed | 0 failed |
-[doctest] assertions: 0 | 0 passed | 0 failed |
+[doctest] test cases: 10 | 10 passed | 0 failed |
+[doctest] assertions:  0 |  0 passed | 0 failed |
 [doctest] Status: SUCCESS!
 Program code.
diff --git a/examples/all_features/test_output/filter_3_junit.txt b/examples/all_features/test_output/filter_3_junit.txt
index 04f78c57..6ea54f98 100644
--- a/examples/all_features/test_output/filter_3_junit.txt
+++ b/examples/all_features/test_output/filter_3_junit.txt
@@ -1,9 +1,15 @@
 <?xml version="1.0" encoding="UTF-8"?>
 
 root
+
+root
+outside of subcase
+outside of subcase
+outside of subcase
 <testsuites>
   <testsuite name="all_features" errors="0" failures="0" tests="0">
     <testcase classname="subcases.cpp" name="lots of nested subcases" status="run"/>
+    <testcase classname="subcases.cpp" name="reentering subcase via regular control flow" status="run"/>
     <testcase classname="subcases.cpp" name="subcases can be used in a separate function as well/from function.../sc1" status="run"/>
     <testcase classname="subcases.cpp" name="  Scenario: vectors can be sized and resized" status="run"/>
     <testcase classname="subcases.cpp" name="test case should fail even though the last subcase passes" status="run"/>
diff --git a/examples/all_features/test_output/filter_3_xml.txt b/examples/all_features/test_output/filter_3_xml.txt
index 1922de26..f662506c 100644
--- a/examples/all_features/test_output/filter_3_xml.txt
+++ b/examples/all_features/test_output/filter_3_xml.txt
@@ -7,6 +7,14 @@
 root
       <OverallResultsAsserts successes="0" failures="0" test_case_success="true"/>
     </TestCase>
+    <TestCase name="reentering subcase via regular control flow" filename="subcases.cpp" line="0">
+
+root
+outside of subcase
+outside of subcase
+outside of subcase
+      <OverallResultsAsserts successes="0" failures="0" test_case_success="true"/>
+    </TestCase>
     <TestCase name="subcases can be used in a separate function as well" filename="subcases.cpp" line="0">
       <SubCase name="from function..." filename="subcases.cpp" line="0">
         <Message type="WARNING" filename="subcases.cpp" line="0">
@@ -59,6 +67,6 @@ root
     </TestCase>
   </TestSuite>
   <OverallResultsAsserts successes="0" failures="0"/>
-  <OverallResultsTestCases successes="9" failures="0"/>
+  <OverallResultsTestCases successes="10" failures="0"/>
 </doctest>
 Program code.
diff --git a/examples/all_features/test_output/no_multi_lane_atomics.txt b/examples/all_features/test_output/no_multi_lane_atomics.txt
index 490dd742..0d3888f6 100644
--- a/examples/all_features/test_output/no_multi_lane_atomics.txt
+++ b/examples/all_features/test_output/no_multi_lane_atomics.txt
@@ -638,6 +638,69 @@ TEST CASE:  part of some TS
 
 test_cases_and_suites.cpp(0): FATAL ERROR: 
 
+
+root
+outside of subcase
+inside subcase 0
+outside of subcase
+inside subcase 1
+outside of subcase
+inside subcase 2
+
+root
+outside of subcase
+also inside 0
+outside of subcase
+also inside 1
+outside of subcase
+also inside 2
+
+root
+outside of subcase
+fail inside 0
+outside of subcase
+===============================================================================
+subcases.cpp(0):
+TEST CASE:  reentering subcase via regular control flow
+
+DEEPEST SUBCASE STACK REACHED (DIFFERENT FROM THE CURRENT ONE):
+
+subcases.cpp(0): FATAL ERROR: 1
+
+
+root
+outside of subcase
+inside outside
+nested twice 0, 0
+nested twice 0, 1
+nested twice 0, 2
+outside of subcase
+inside outside
+nested twice 1, 0
+nested twice 1, 1
+nested twice 1, 2
+outside of subcase
+inside outside
+nested twice 2, 0
+nested twice 2, 1
+nested twice 2, 2
+
+root
+outside of subcase
+inside outside
+also twice 0, 0
+also twice 0, 1
+also twice 0, 2
+outside of subcase
+inside outside
+also twice 1, 0
+also twice 1, 1
+also twice 1, 2
+outside of subcase
+inside outside
+also twice 2, 0
+also twice 2, 1
+also twice 2, 2
 ===============================================================================
 test_cases_and_suites.cpp(0):
 TEST CASE:  should fail because of an exception
@@ -814,7 +877,7 @@ TEST CASE:  without a funny name:
 subcases.cpp(0): MESSAGE: Nooo
 
 ===============================================================================
-[doctest] test cases:  79 |  30 passed |  49 failed |
-[doctest] assertions: 215 | 100 passed | 115 failed |
+[doctest] test cases:  80 |  30 passed |  50 failed |
+[doctest] assertions: 216 | 100 passed | 116 failed |
 [doctest] Status: FAILURE!
 Program code.
diff --git a/examples/all_features/test_output/no_multithreading.txt b/examples/all_features/test_output/no_multithreading.txt
index 490dd742..0d3888f6 100644
--- a/examples/all_features/test_output/no_multithreading.txt
+++ b/examples/all_features/test_output/no_multithreading.txt
@@ -638,6 +638,69 @@ TEST CASE:  part of some TS
 
 test_cases_and_suites.cpp(0): FATAL ERROR: 
 
+
+root
+outside of subcase
+inside subcase 0
+outside of subcase
+inside subcase 1
+outside of subcase
+inside subcase 2
+
+root
+outside of subcase
+also inside 0
+outside of subcase
+also inside 1
+outside of subcase
+also inside 2
+
+root
+outside of subcase
+fail inside 0
+outside of subcase
+===============================================================================
+subcases.cpp(0):
+TEST CASE:  reentering subcase via regular control flow
+
+DEEPEST SUBCASE STACK REACHED (DIFFERENT FROM THE CURRENT ONE):
+
+subcases.cpp(0): FATAL ERROR: 1
+
+
+root
+outside of subcase
+inside outside
+nested twice 0, 0
+nested twice 0, 1
+nested twice 0, 2
+outside of subcase
+inside outside
+nested twice 1, 0
+nested twice 1, 1
+nested twice 1, 2
+outside of subcase
+inside outside
+nested twice 2, 0
+nested twice 2, 1
+nested twice 2, 2
+
+root
+outside of subcase
+inside outside
+also twice 0, 0
+also twice 0, 1
+also twice 0, 2
+outside of subcase
+inside outside
+also twice 1, 0
+also twice 1, 1
+also twice 1, 2
+outside of subcase
+inside outside
+also twice 2, 0
+also twice 2, 1
+also twice 2, 2
 ===============================================================================
 test_cases_and_suites.cpp(0):
 TEST CASE:  should fail because of an exception
@@ -814,7 +877,7 @@ TEST CASE:  without a funny name:
 subcases.cpp(0): MESSAGE: Nooo
 
 ===============================================================================
-[doctest] test cases:  79 |  30 passed |  49 failed |
-[doctest] assertions: 215 | 100 passed | 115 failed |
+[doctest] test cases:  80 |  30 passed |  50 failed |
+[doctest] assertions: 216 | 100 passed | 116 failed |
 [doctest] Status: FAILURE!
 Program code.
diff --git a/examples/all_features/test_output/subcases.cpp.txt b/examples/all_features/test_output/subcases.cpp.txt
index 0acc7bf1..8ce6f4e7 100644
--- a/examples/all_features/test_output/subcases.cpp.txt
+++ b/examples/all_features/test_output/subcases.cpp.txt
@@ -16,6 +16,69 @@ TEST CASE:  lots of nested subcases
 
 subcases.cpp(0): FATAL ERROR: 
 
+
+root
+outside of subcase
+inside subcase 0
+outside of subcase
+inside subcase 1
+outside of subcase
+inside subcase 2
+
+root
+outside of subcase
+also inside 0
+outside of subcase
+also inside 1
+outside of subcase
+also inside 2
+
+root
+outside of subcase
+fail inside 0
+outside of subcase
+===============================================================================
+subcases.cpp(0):
+TEST CASE:  reentering subcase via regular control flow
+
+DEEPEST SUBCASE STACK REACHED (DIFFERENT FROM THE CURRENT ONE):
+
+subcases.cpp(0): FATAL ERROR: 1
+
+
+root
+outside of subcase
+inside outside
+nested twice 0, 0
+nested twice 0, 1
+nested twice 0, 2
+outside of subcase
+inside outside
+nested twice 1, 0
+nested twice 1, 1
+nested twice 1, 2
+outside of subcase
+inside outside
+nested twice 2, 0
+nested twice 2, 1
+nested twice 2, 2
+
+root
+outside of subcase
+inside outside
+also twice 0, 0
+also twice 0, 1
+also twice 0, 2
+outside of subcase
+inside outside
+also twice 1, 0
+also twice 1, 1
+also twice 1, 2
+outside of subcase
+inside outside
+also twice 2, 0
+also twice 2, 1
+also twice 2, 2
 ===============================================================================
 subcases.cpp(0):
 TEST CASE:  subcases can be used in a separate function as well
@@ -225,7 +288,7 @@ TEST CASE:  without a funny name:
 subcases.cpp(0): MESSAGE: Nooo
 
 ===============================================================================
-[doctest] test cases:  9 |  5 passed | 4 failed |
-[doctest] assertions: 25 | 19 passed | 6 failed |
+[doctest] test cases: 10 |  5 passed | 5 failed |
+[doctest] assertions: 26 | 19 passed | 7 failed |
 [doctest] Status: FAILURE!
 Program code.
diff --git a/examples/all_features/test_output/subcases.cpp_junit.txt b/examples/all_features/test_output/subcases.cpp_junit.txt
index d1c82380..0526b7d0 100644
--- a/examples/all_features/test_output/subcases.cpp_junit.txt
+++ b/examples/all_features/test_output/subcases.cpp_junit.txt
@@ -10,11 +10,71 @@ root
 
 root
 2
+
+root
+outside of subcase
+inside subcase 0
+outside of subcase
+inside subcase 1
+outside of subcase
+inside subcase 2
+
+root
+outside of subcase
+also inside 0
+outside of subcase
+also inside 1
+outside of subcase
+also inside 2
+
+root
+outside of subcase
+fail inside 0
+outside of subcase
+
+root
+outside of subcase
+inside outside
+nested twice 0, 0
+nested twice 0, 1
+nested twice 0, 2
+outside of subcase
+inside outside
+nested twice 1, 0
+nested twice 1, 1
+nested twice 1, 2
+outside of subcase
+inside outside
+nested twice 2, 0
+nested twice 2, 1
+nested twice 2, 2
+
+root
+outside of subcase
+inside outside
+also twice 0, 0
+also twice 0, 1
+also twice 0, 2
+outside of subcase
+inside outside
+also twice 1, 0
+also twice 1, 1
+also twice 1, 2
+outside of subcase
+inside outside
+also twice 2, 0
+also twice 2, 1
+also twice 2, 2
 <testsuites>
-  <testsuite name="all_features" errors="4" failures="5" tests="25">
+  <testsuite name="all_features" errors="4" failures="5" tests="26">
     <testcase classname="subcases.cpp" name="lots of nested subcases" status="run"/>
     <testcase classname="subcases.cpp" name="lots of nested subcases" status="run"/>
     <testcase classname="subcases.cpp" name="lots of nested subcases" status="run"/>
+    <testcase classname="subcases.cpp" name="reentering subcase via regular control flow" status="run"/>
+    <testcase classname="subcases.cpp" name="reentering subcase via regular control flow" status="run"/>
+    <testcase classname="subcases.cpp" name="reentering subcase via regular control flow" status="run"/>
+    <testcase classname="subcases.cpp" name="reentering subcase via regular control flow" status="run"/>
+    <testcase classname="subcases.cpp" name="reentering subcase via regular control flow" status="run"/>
     <testcase classname="subcases.cpp" name="subcases can be used in a separate function as well/from function.../sc1" status="run"/>
     <testcase classname="subcases.cpp" name="subcases can be used in a separate function as well/from function.../sc2" status="run"/>
     <testcase classname="subcases.cpp" name="  Scenario: vectors can be sized and resized/   Given: A vector with some items/    When: the size is increased/    Then: the size and capacity change" status="run">
diff --git a/examples/all_features/test_output/subcases.cpp_xml.txt b/examples/all_features/test_output/subcases.cpp_xml.txt
index ad208bb4..465fcd0f 100644
--- a/examples/all_features/test_output/subcases.cpp_xml.txt
+++ b/examples/all_features/test_output/subcases.cpp_xml.txt
@@ -31,6 +31,133 @@ root
       </SubCase>
       <OverallResultsAsserts successes="0" failures="1" test_case_success="false"/>
     </TestCase>
+    <TestCase name="reentering subcase via regular control flow" filename="subcases.cpp" line="0">
+
+root
+outside of subcase
+      <SubCase filename="subcases.cpp" line="0">
+inside subcase 0
+      </SubCase>
+outside of subcase
+      <SubCase filename="subcases.cpp" line="0">
+inside subcase 1
+      </SubCase>
+outside of subcase
+      <SubCase filename="subcases.cpp" line="0">
+inside subcase 2
+      </SubCase>
+
+root
+outside of subcase
+      <SubCase filename="subcases.cpp" line="0">
+also inside 0
+      </SubCase>
+outside of subcase
+      <SubCase filename="subcases.cpp" line="0">
+also inside 1
+      </SubCase>
+outside of subcase
+      <SubCase filename="subcases.cpp" line="0">
+also inside 2
+      </SubCase>
+
+root
+outside of subcase
+      <SubCase filename="subcases.cpp" line="0">
+fail inside 0
+      </SubCase>
+outside of subcase
+      <SubCase filename="subcases.cpp" line="0">
+        <Message type="FATAL ERROR" filename="subcases.cpp" line="0">
+          <Text>
+            1
+          </Text>
+        </Message>
+      </SubCase>
+
+root
+outside of subcase
+      <SubCase filename="subcases.cpp" line="0">
+inside outside
+        <SubCase filename="subcases.cpp" line="0">
+nested twice 0, 0
+        </SubCase>
+        <SubCase filename="subcases.cpp" line="0">
+nested twice 0, 1
+        </SubCase>
+        <SubCase filename="subcases.cpp" line="0">
+nested twice 0, 2
+        </SubCase>
+      </SubCase>
+outside of subcase
+      <SubCase filename="subcases.cpp" line="0">
+inside outside
+        <SubCase filename="subcases.cpp" line="0">
+nested twice 1, 0
+        </SubCase>
+        <SubCase filename="subcases.cpp" line="0">
+nested twice 1, 1
+        </SubCase>
+        <SubCase filename="subcases.cpp" line="0">
+nested twice 1, 2
+        </SubCase>
+      </SubCase>
+outside of subcase
+      <SubCase filename="subcases.cpp" line="0">
+inside outside
+        <SubCase filename="subcases.cpp" line="0">
+nested twice 2, 0
+        </SubCase>
+        <SubCase filename="subcases.cpp" line="0">
+nested twice 2, 1
+        </SubCase>
+        <SubCase filename="subcases.cpp" line="0">
+nested twice 2, 2
+        </SubCase>
+      </SubCase>
+
+root
+outside of subcase
+      <SubCase filename="subcases.cpp" line="0">
+inside outside
+        <SubCase filename="subcases.cpp" line="0">
+also twice 0, 0
+        </SubCase>
+        <SubCase filename="subcases.cpp" line="0">
+also twice 0, 1
+        </SubCase>
+        <SubCase filename="subcases.cpp" line="0">
+also twice 0, 2
+        </SubCase>
+      </SubCase>
+outside of subcase
+      <SubCase filename="subcases.cpp" line="0">
+inside outside
+        <SubCase filename="subcases.cpp" line="0">
+also twice 1, 0
+        </SubCase>
+        <SubCase filename="subcases.cpp" line="0">
+also twice 1, 1
+        </SubCase>
+        <SubCase filename="subcases.cpp" line="0">
+also twice 1, 2
+        </SubCase>
+      </SubCase>
+outside of subcase
+      <SubCase filename="subcases.cpp" line="0">
+inside outside
+        <SubCase filename="subcases.cpp" line="0">
+also twice 2, 0
+        </SubCase>
+        <SubCase filename="subcases.cpp" line="0">
+also twice 2, 1
+        </SubCase>
+        <SubCase filename="subcases.cpp" line="0">
+also twice 2, 2
+        </SubCase>
+      </SubCase>
+      <OverallResultsAsserts successes="0" failures="1" test_case_success="false"/>
+    </TestCase>
     <TestCase name="subcases can be used in a separate function as well" filename="subcases.cpp" line="0">
       <SubCase name="from function..." filename="subcases.cpp" line="0">
         <Message type="WARNING" filename="subcases.cpp" line="0">
@@ -269,7 +396,7 @@ root
       <OverallResultsAsserts successes="0" failures="0" test_case_success="true"/>
     </TestCase>
   </TestSuite>
-  <OverallResultsAsserts successes="19" failures="6"/>
-  <OverallResultsTestCases successes="5" failures="4"/>
+  <OverallResultsAsserts successes="19" failures="7"/>
+  <OverallResultsTestCases successes="5" failures="5"/>
 </doctest>
 Program code.