[hbelusca] 71591: [CONSRV] - Remove a wrong assertion that I introduced in r70281 concerning Console->LinePos. - Fix some boundary conditions. - Completely reset line discipline variables when the ...

Author: hbelusca
Date: Tue Jun  7 22:52:44 2016
New Revision: 71591

URL: http://svn.reactos.org/svn/reactos?rev=71591&view=rev
Log:
[CONSRV]
- Remove a wrong assertion that I introduced in r70281 concerning Console->LinePos.
- Fix some boundary conditions.
- Completely reset line discipline variables when the line buffer is freed.
- Fix a potential buffer overrun in the case ReadControl->nInitialChars was larger than Console->LineMaxSize (the size of Console->LineBuffer), which serves to initialize Console->LineSize, Console->LinePos, and copy nInitialChars characters from user buffer.
CORE-11380 CORE-10997 #resolve

Modified:
    trunk/reactos/win32ss/user/winsrv/consrv/frontends/terminal.c

Modified: trunk/reactos/win32ss/user/winsrv/consrv/frontends/terminal.c
URL: http://svn.reactos.org/svn/reactos/trunk/reactos/win32ss/user/winsrv/consrv/...
==============================================================================
--- trunk/reactos/win32ss/user/winsrv/consrv/frontends/terminal.c	[iso-8859-1] (original)
+++ trunk/reactos/win32ss/user/winsrv/consrv/frontends/terminal.c	[iso-8859-1] Tue Jun  7 22:52:44 2016
@@ -330,7 +330,13 @@
         {
             /* Start a new line */
             Console->LineMaxSize = max(256, NumCharsToRead);
-            ASSERT(ReadControl->nInitialChars <= Console->LineMaxSize);
+
+            /*
+             * Fixup ReadControl->nInitialChars in case the number of initial
+             * characters is bigger than the number of characters to be read.
+             * It will always be, lesser than or equal to Console->LineMaxSize.
+             */
+            ReadControl->nInitialChars = min(ReadControl->nInitialChars, NumCharsToRead);

Console->LineBuffer = ConsoleAllocHeap(0, Console->LineMaxSize * sizeof(WCHAR));
             if (Console->LineBuffer == NULL) return STATUS_NO_MEMORY;
@@ -346,7 +352,7 @@
              * worry about ANSI <-> Unicode conversion.
              */
             memcpy(Console->LineBuffer, Buffer, Console->LineSize * sizeof(WCHAR));
-            if (Console->LineSize == Console->LineMaxSize)
+            if (Console->LineSize >= Console->LineMaxSize)
             {
                 Console->LineComplete = TRUE;
                 Console->LinePos = 0;
@@ -356,7 +362,7 @@
         /* If we don't have a complete line yet, process the pending input */
         while (!Console->LineComplete && !IsListEmpty(&InputBuffer->InputEvents))
         {
-            /* Remove input event from queue */
+            /* Remove an input event from the queue */
             CurrentEntry = RemoveHeadList(&InputBuffer->InputEvents);
             if (IsListEmpty(&InputBuffer->InputEvents))
             {
@@ -378,12 +384,14 @@
         /* Check if we have a complete line to read from */
         if (Console->LineComplete)
         {
-            // NOTE: I want to check whether we always set LinePos to zero
-            // when LineComplete is set to TRUE.
-            // Basically, we are going to use LinePos as 'i'.
-            ASSERT(Console->LinePos == 0);
-
-            while (i < NumCharsToRead && Console->LinePos != Console->LineSize)
+            /*
+             * Console->LinePos keeps the next position of the character to read
+             * in the line buffer across the different calls of the function,
+             * so that the line buffer can be read by chunks after all the input
+             * has been buffered.
+             */
+
+            while (i < NumCharsToRead && Console->LinePos < Console->LineSize)
             {
                 WCHAR Char = Console->LineBuffer[Console->LinePos++];

@@ -398,11 +406,14 @@
                 ++i;
             }

-            if (Console->LinePos == Console->LineSize)
-            {
-                /* Entire line has been read */
+            if (Console->LinePos >= Console->LineSize)
+            {
+                /* The entire line has been read */
                 ConsoleFreeHeap(Console->LineBuffer);
                 Console->LineBuffer = NULL;
+                Console->LinePos = Console->LineMaxSize = Console->LineSize = 0;
+                // Console->LineComplete = Console->LineUpPressed = FALSE;
+                Console->LineComplete = FALSE;
             }

Status = STATUS_SUCCESS;
@@ -415,7 +426,7 @@
         /* Character input */
         while (i < NumCharsToRead && !IsListEmpty(&InputBuffer->InputEvents))
         {
-            /* Remove input event from queue */
+            /* Remove an input event from the queue */
             CurrentEntry = RemoveHeadList(&InputBuffer->InputEvents);
             if (IsListEmpty(&InputBuffer->InputEvents))
             {