Skip the AST analysis when command-line input has any parsing errors

PSReadLine/History.cs

@@ -565,10 +565,24 @@ public static AddToHistoryOption GetDefaultAddToHistoryOption(string line)
                 return AddToHistoryOption.MemoryAndFile;
             }
 
+            // The input contains at least one match of some sensitive patterns, so now we need to further
+            // analyze the input using the ASTs to see if it should actually be considered sensitive.
             bool isSensitive = false;
+            ParseError[] parseErrors = _singleton._parseErrors;
+
+            // We need to compare the text here, instead of simply checking whether or not '_ast' is null.
+            // This is because we may need to update from history file in the middle of editing an input,
+            // and in that case, the '_ast' may be not-null, but it was not parsed from 'line'.
             Ast ast = string.Equals(_singleton._ast?.Extent.Text, line)
                 ? _singleton._ast
-                : Parser.ParseInput(line, out _, out _);
+                : Parser.ParseInput(line, out _, out parseErrors);
+
+            if (parseErrors != null && parseErrors.Length > 0)
+            {
+                // If the input has any parsing errors, we cannot reliably analyze the AST. We just consider
+                // it sensitive in this case, given that it contains matches of our sensitive pattern.
+                return AddToHistoryOption.MemoryOnly;
+            }
 
             do
             {

PSReadLine/ReadLine.cs

@@ -721,6 +721,7 @@ private void Initialize(Runspace runspace, EngineIntrinsics engineIntrinsics)
             _mark = 0;
             _emphasisStart = -1;
             _emphasisLength = 0;
+            _ast = null;
             _tokens = null;
             _parseErrors = null;
             _inputAccepted = false;

test/HistoryTest.cs

@@ -201,7 +201,8 @@ public void SensitiveHistoryDefaultBehavior_Two()
                 "Get-SecretInfo -Name mytoken; Get-SecretVault; Register-SecretVault; Remove-Secret apikey; Set-Secret", // 'Set-Secret' Not saved to file.
                 "Set-SecretInfo -Name apikey; Set-SecretVaultDefault; Test-SecretVault; Unlock-SecretVault -password $pwd; Unregister-SecretVault -SecretVault vaultInfo",
                 "Get-ResultFromTwo -Secret1 (Get-Secret -Name blah -AsPlainText) -Secret2 $secret2",
-                "Get-ResultFromTwo -Secret1 (Get-Secret -Name blah -AsPlainText) -Secret2 sdv87ysdfayf798hfasd8f7ha" // '-Secret2' has expr-value argument. Not saved to file.
+                "Get-ResultFromTwo -Secret1 (Get-Secret -Name blah -AsPlainText) -Secret2 sdv87ysdfayf798hfasd8f7ha", // '-Secret2' has expr-value argument. Not saved to file.
+                "$environment -brand $brand -userBitWardenEmail $bwuser -userBitWardenPassword $bwpass" // '-userBitWardenPassword' matches sensitive pattern and it has parsing error. Not save to file.
             };
 
             string[] expectedSavedItems = new[] {