Consider elif inner instructions as branching points (PY-23003)

python/src/com/jetbrains/python/codeInsight/controlflow/PyControlFlowBuilder.java

@@ -360,9 +360,9 @@ public class PyControlFlowBuilder extends PyRecursiveElementVisitor {
       assertionEvaluator = new PyTypeAssertionEvaluator();
       if (condition != null) {
         lastCondition = condition;
-        lastBranchingPoints = getPrevInstructions(lastCondition);
         condition.accept(this);
         condition.accept(assertionEvaluator);
+        lastBranchingPoints = getPrevInstructions(lastCondition);
       }
       // Set the head as the last instruction of condition
       getPrevInstructions(lastCondition).forEach(pair -> myBuilder.addPendingEdge(pair.getFirst(), pair.getSecond()));

python/testData/codeInsight/controlflow/manyifs.txt

@@ -7,9 +7,9 @@
 6(7) element: PyStatementList. Condition: a == b:true
 7(8) element: PyAssignmentStatement
 8(25) WRITE ACCESS: var
-9(10,22) element: PyIfPartElif. Condition: a == b:false
+9(10) element: PyIfPartElif. Condition: a == b:false
 10(11) READ ACCESS: aa
-11(12) READ ACCESS: bb
+11(12,22) READ ACCESS: bb
 12(13) element: PyIfPartElif. Condition: aa == bb:true
 13(14) element: PyAssignmentStatement
 14(15) READ ACCESS: same_changet_expression

python/testData/codeInsight/controlflow/trytry.txt

@@ -20,17 +20,17 @@
 19(20,22,37) READ ACCESS: x
 20(21) element: PyStatementList. Condition: x == 0:true
 21(37,40) element: PyBreakStatement
-22(23,26,37) element: PyIfPartElif. Condition: x == 0:false
-23(24,37) READ ACCESS: x
+22(23,37) element: PyIfPartElif. Condition: x == 0:false
+23(24,26,37) READ ACCESS: x
 24(25,37) element: PyIfPartElif. Condition: x == 1:true
 25(7,37) element: PyContinueStatement
-26(27,31,37) element: PyIfPartElif. Condition: x == 1:false
-27(28,37) READ ACCESS: x
+26(27,37) element: PyIfPartElif. Condition: x == 1:false
+27(28,31,37) READ ACCESS: x
 28(29,37) element: PyIfPartElif. Condition: x == 2:true
 29(30,37) element: PyRaiseStatement
 30(37) READ ACCESS: Exception
-31(32,35,37) element: PyIfPartElif. Condition: x == 2:false
-32(33,37) READ ACCESS: x
+31(32,37) element: PyIfPartElif. Condition: x == 2:false
+32(33,35,37) READ ACCESS: x
 33(34,37) element: PyIfPartElif. Condition: x == 3:true
 34(37) element: PyReturnStatement
 35(36,37) element: PyAssignmentStatement

python/testSrc/com/jetbrains/python/fixtures/PyInspectionTestCase.java

@@ -2,6 +2,7 @@ package com.jetbrains.python.fixtures;
 
 import com.intellij.codeInspection.ex.InspectionProfileImpl;
 import com.intellij.psi.PsiFile;
+import com.jetbrains.python.PythonFileType;
 import com.jetbrains.python.inspections.PyInspection;
 import org.jetbrains.annotations.NotNull;
 
@@ -43,6 +44,12 @@ public abstract class PyInspectionTestCase extends PyTestCase {
     assertSdkRootsNotParsed(currentFile);
   }
 
+  protected void doTestByText(@NotNull String text) {
+    final PsiFile currentFile = myFixture.configureByText(PythonFileType.INSTANCE, text);
+    configureInspection();
+    assertSdkRootsNotParsed(currentFile);
+  }
+
   protected void doMultiFileTest() {
     doMultiFileTest("a.py");
   }

python/testSrc/com/jetbrains/python/inspections/PyRedeclarationInspectionTest.java

@@ -169,6 +169,20 @@ public class PyRedeclarationInspectionTest extends PyInspectionTestCase {
     doTest();
   }
 
+  // PY-23003
+  public void testVariableUsedInElIf() {
+    doTestByText(
+      "for file in ['test_file']:\n" +
+      "    block = False\n" +
+      "    if a:\n" +
+      "        block = True\n" +
+      "    elif block and b:\n" +
+      "        block = False\n" +
+      "    else:\n" +
+      "        print(c)"
+    );
+  }
+
   @NotNull
   @Override
   protected Class<? extends PyInspection> getInspectionClass() {