Fix section filtering to make sense

Specifically, this commit makes the `-c`/`--section` parameter
strictly ordered and hierarchical, unlike how it behaved before,
which was a huge mess -- see #3038 for details.

Closes #3038

tests/SelfTest/IntrospectiveTests/Details.tests.cpp

@@ -7,6 +7,7 @@
 // SPDX-License-Identifier: BSL-1.0
 
 #include <catch2/catch_test_macros.hpp>
+#include <catch2/generators/catch_generators.hpp>
 #include <catch2/internal/catch_enforce.hpp>
 #include <catch2/internal/catch_case_insensitive_comparisons.hpp>
 #include <catch2/internal/catch_optional.hpp>
@@ -170,3 +171,64 @@ TEST_CASE( "Decomposer checks that the argument is 0 when handling "
 
     CATCH_INTERNAL_STOP_WARNINGS_SUPPRESSION
 }
+
+
+TEST_CASE( "foo", "[approvals]" ) {
+    SECTION( "A" ) {
+        SECTION( "B1" ) { REQUIRE( true ); }
+        SECTION( "B2" ) { REQUIRE( true ); }
+        SECTION( "B3" ) { REQUIRE( true ); }
+    }
+}
+
+TEST_CASE( "bar", "[approvals]" ) {
+    REQUIRE( true );
+    SECTION( "A" ) {
+        SECTION( "B1" ) { REQUIRE( true ); }
+        SECTION( "B2" ) { REQUIRE( true ); }
+        SECTION( "B3" ) { REQUIRE( true ); }
+    }
+    REQUIRE( true );
+}
+
+TEST_CASE( "baz", "[approvals]" ) {
+    SECTION( "A" ) { REQUIRE( true ); }
+    auto _ = GENERATE( 1, 2, 3 );
+    (void)_;
+    SECTION( "B" ) { REQUIRE( true ); }
+}
+
+TEST_CASE( "qux", "[approvals]" ) {
+    REQUIRE( true );
+    SECTION( "A" ) { REQUIRE( true ); }
+    auto _ = GENERATE( 1, 2, 3 );
+    (void)_;
+    SECTION( "B" ) { REQUIRE( true ); }
+    REQUIRE( true );
+}
+
+TEST_CASE( "corge", "[approvals]" ) {
+    REQUIRE( true );
+    SECTION( "A" ) {
+        REQUIRE( true );
+    }
+    auto i = GENERATE( 1, 2, 3 );
+    DYNAMIC_SECTION( "i=" << i ) {
+        REQUIRE( true );
+    }
+    REQUIRE( true );
+}
+
+TEST_CASE("grault", "[approvals]") {
+    REQUIRE( true );
+    SECTION( "A" ) {
+        REQUIRE( true );
+    }
+    SECTION("B") {
+        auto i = GENERATE( 1, 2, 3 );
+        DYNAMIC_SECTION( "i=" << i ) {
+            REQUIRE( true );
+        }
+    }
+    REQUIRE( true );
+}

tests/SelfTest/UsageTests/Tricky.tests.cpp

@@ -354,27 +354,9 @@ TEST_CASE("#1514: stderr/stdout is not captured in tests aborted by an exception
     FAIL("1514");
 }
 
-
-TEST_CASE( "#2025: -c shouldn't cause infinite loop", "[sections][generators][regression][.approvals]" ) {
-    SECTION( "Check cursor from buffer offset" ) {
-        auto bufPos = GENERATE_REF( range( 0, 44 ) );
-        WHEN( "Buffer position is " << bufPos ) { REQUIRE( 1 == 1 ); }
-    }
-}
-
 TEST_CASE("#2025: original repro", "[sections][generators][regression][.approvals]") {
     auto fov = GENERATE(true, false);
     DYNAMIC_SECTION("fov_" << fov) {
         std::cout << "inside with fov: " << fov << '\n';
     }
 }
-
-TEST_CASE("#2025: same-level sections", "[sections][generators][regression][.approvals]") {
-    SECTION("A") {
-        SUCCEED();
-    }
-    auto i = GENERATE(1, 2, 3);
-    SECTION("B") {
-        REQUIRE(i < 4);
-    }
-}