[PATCH] ShellPkg/UefiShellLevel2CommandsLib: Fix ls on entirely empty directories.

["Marvin Häuser" <Marvin.Haeuser@outlook.com>]

Currently, when 'ls' is run on an entirely empty directory (this
includes not having '.' and '..'), the output is always 'File not
found'. For when not filtering its children, this patch rather
displays the usual header and footer.

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Marvin Haeuser <Marvin.Haeuser@outlook.com>
---
 ShellPkg/Library/UefiShellLevel2CommandsLib/Ls.c | 33 +++++++++++++++++---
 1 file changed, 28 insertions(+), 5 deletions(-)

diff --git a/ShellPkg/Library/UefiShellLevel2CommandsLib/Ls.c b/ShellPkg/Library/UefiShellLevel2CommandsLib/Ls.c
index 7d2e15f5206b..324dcb6091c8 100644
--- a/ShellPkg/Library/UefiShellLevel2CommandsLib/Ls.c
+++ b/ShellPkg/Library/UefiShellLevel2CommandsLib/Ls.c
@@ -423,6 +423,8 @@ FileTimeToLocalTime (
   @param[in] Found          Set to TRUE, if anyone were found.
   @param[in] Count          The count of bits enabled in Attribs.
   @param[in] TimeZone       The current time zone offset.
+  @param[in] ListUnfiltered TRUE to request listing the directory contents
+                            unfiltered.
 
   @retval SHELL_SUCCESS     the printing was sucessful.
 **/
@@ -435,7 +437,8 @@ PrintLsOutput(
   IN CONST CHAR16  *SearchString,
   IN       BOOLEAN *Found,
   IN CONST UINTN   Count,
-  IN CONST INT16   TimeZone
+  IN CONST INT16   TimeZone,
+  IN CONST BOOLEAN ListUnfiltered
   )
 {
   EFI_STATUS            Status;
@@ -561,7 +564,7 @@ PrintLsOutput(
       HeaderPrinted = TRUE;
     }
 
-    if (!Sfo && ShellStatus != SHELL_ABORTED) {
+    if (!Sfo && ShellStatus != SHELL_ABORTED && HeaderPrinted) {
       PrintNonSfoFooter(FileCount, FileSize, DirCount);
     }
   }
@@ -608,7 +611,8 @@ PrintLsOutput(
             SearchString,
             &FoundOne,
             Count,
-            TimeZone);
+            TimeZone,
+            FALSE);
             
           //
           // Since it's running recursively, we have to break immediately when returned SHELL_ABORTED
@@ -625,7 +629,21 @@ PrintLsOutput(
   ShellCloseFileMetaArg(&ListHead);
 
   if (Found == NULL && !FoundOne) {
-    return (SHELL_NOT_FOUND);
+    if (ListUnfiltered) {
+      //
+      // When running "ls" without any filtering request, avoid outputing
+      // "File not found" when the directory is entirely empty, but print
+      // header and footer stating "0 File(s), 0 Dir(s)".
+      //
+      if (!Sfo) {
+        PrintNonSfoHeader (RootPath);
+        if (ShellStatus != SHELL_ABORTED) {
+          PrintNonSfoFooter (FileCount, FileSize, DirCount);
+        }
+      }
+    } else {
+      return (SHELL_NOT_FOUND);
+    }
   }
 
   if (Found != NULL) {
@@ -668,6 +686,7 @@ ShellCommandRunLs (
   UINTN         Size;
   EFI_TIME      TheTime;
   CHAR16        *SearchString;
+  BOOLEAN       ListUnfiltered;
 
   Size                = 0;
   FullPath            = NULL;
@@ -679,6 +698,7 @@ ShellCommandRunLs (
   SearchString        = NULL;
   CurDir              = NULL;
   Count               = 0;
+  ListUnfiltered      = FALSE;
 
   //
   // initialize the shell lib (we must be in non-auto-init...)
@@ -774,6 +794,7 @@ ShellCommandRunLs (
             ShellStatus = SHELL_NOT_FOUND;
             ShellPrintHiiEx(-1, -1, NULL, STRING_TOKEN (STR_GEN_NO_CWD), gShellLevel2HiiHandle, L"ls");  
           }
+          ListUnfiltered = TRUE;
           //
           // Copy to the 2 strings for starting path and file search string
           //
@@ -814,6 +835,7 @@ ShellCommandRunLs (
               //
               // is listing ends with a directory, then we list all files in that directory
               //
+              ListUnfiltered = TRUE;
               StrnCatGrow(&SearchString, NULL, L"*", 0);
             } else {
               //
@@ -845,7 +867,8 @@ ShellCommandRunLs (
             SearchString,
             NULL,
             Count,
-            TheTime.TimeZone
+            TheTime.TimeZone,
+            ListUnfiltered
            );
           if (ShellStatus == SHELL_NOT_FOUND) {
             ShellPrintHiiEx(-1, -1, NULL, STRING_TOKEN (STR_LS_FILE_NOT_FOUND), gShellLevel2HiiHandle, L"ls", FullPath);  
-- 
2.17.0.windows.1