Fix ReplaceDbNameInFile to only replace filename, not directory path

Fixes #9656

The issue was that ReplaceDbNameInFile was replacing the database name in the full file path (including directory), which caused the directory path to be incorrectly modified. This led to 'file already exists and owned by another database' errors because the code would look in the wrong directory or create invalid paths.

The fix moves the database name replacement to apply only to the basename (filename without directory), after extracting the directory path and before reconstructing the full path. This ensures the directory structure remains intact while only the filename gets the database name replaced.

Changes: Modified Format-DbaBackupInformation.ps1 to replace database name in basename only, not full path. Added regression test for #9656 to prevent this issue from recurring.

Co-authored-by: Chrissy LeMaire <potatoqualitee@users.noreply.github.com>

Author: github-actions[bot]

public/Format-DbaBackupInformation.ps1

@@ -186,14 +186,14 @@ function Format-DbaBackupInformation {
                         $_.PhysicalName = $FileMapping[$_.LogicalName]
                     }
                 } else {
-                    if ($ReplaceDbNameInFile -eq $true) {
-                        $_.PhysicalName = $_.PhysicalName -Replace $History.OriginalDatabase, $History.Database
-                    }
                     Write-Message -Message " 1 PhysicalName = $($_.PhysicalName) " -Level Verbose
                     $Pname = [System.Io.FileInfo]$_.PhysicalName
                     $RestoreDir = $Pname.DirectoryName
                     # Handle MacOS returning full path for BaseName
                     $baseName = $Pname.BaseName.Split($PathSep)[-1]
+                    if ($ReplaceDbNameInFile -eq $true) {
+                        $baseName = $baseName -Replace $History.OriginalDatabase, $History.Database
+                    }
                     if ($_.Type -eq 'D' -or $_.FileType -eq 'D') {
                         if ('' -ne $DataFileDirectory) {
                             $RestoreDir = $DataFileDirectory

tests/Restore-DbaDatabase.Tests.ps1

@@ -220,6 +220,24 @@ Describe $CommandName -Tag IntegrationTests {
     }
 
 
+    Context "ReplaceDbNameInFile regression test for #9656" {
+        BeforeAll {
+            $null = Get-DbaDatabase -SqlInstance $TestConfig.instance2 -ExcludeSystem -EnableException | Remove-DbaDatabase -EnableException
+        }
+
+        It "Should replace database name in file basename only, not in directory path" {
+            $scriptOutput = Restore-DbaDatabase -SqlInstance $TestConfig.instance2 -Path "$($TestConfig.appveyorlabrepo)\singlerestore\singlerestore.bak" -DatabaseName "NewDatabaseName" -ReplaceDbNameInFile -WithReplace -OutputScriptOnly
+            $scriptOutput | Should -BeLike "*NewDatabaseName*"
+            $scriptOutput | Should -Not -BeLike "*singlerestore\NewDatabaseName\*"
+        }
+
+        It "Should generate valid MOVE statements with replaced database name" {
+            $scriptOutput = Restore-DbaDatabase -SqlInstance $TestConfig.instance2 -Path "$($TestConfig.appveyorlabrepo)\singlerestore\singlerestore.bak" -DatabaseName "ReplacedDbName" -ReplaceDbNameInFile -WithReplace -OutputScriptOnly
+            $scriptOutput | Should -Match "MOVE.*ReplacedDbName"
+        }
+    }
+
+
     Context "Test restoring as other login #6992" {
         BeforeAll {
             $null = Get-DbaDatabase -SqlInstance $TestConfig.instance2 -ExcludeSystem -EnableException | Remove-DbaDatabase -EnableException