Create a new version of paste:

diff -r c42a62268eee src/fileio.cpp
--- a/src/fileio.cpp	Fri Apr 29 18:35:36 2011 +0100
+++ b/src/fileio.cpp	Tue May 10 20:02:29 2011 +0100
@@ -469,6 +469,53 @@
 	return true;
 }
 
+/** 
+ * Check a grf for a readme.txt file.
+ * @param cfg The GRFConfig to check.
+ * @return true is the GRF is packaged with a readme.txt file.
+ * @note a GRF can only have a readme if it is inside a tar archive.
+ */
+bool GrfHasReadme(const GRFConfig *cfg)
+{
+	if (!FindReadme(cfg)) return false;
+	return true;
+}
+
+/**
+ * Find a readme.txt file.
+ * @param cfg The GRFConfig to check.
+ * @return The path to the readme, false if no readme found.
+ */
+char *FindReadme(const GRFConfig *cfg)
+{
+	if (cfg == NULL || cfg->filename == NULL) return false;
+
+	const char *slash = strrchr(cfg->filename, PATHSEPCHAR);
+	if (slash == NULL) return false;
+	int prefix_length = slash - cfg->filename + 1; // Including the path separator.
+	if (prefix_length + 10 + 1 > MAX_PATH) return false; // "foo/" + "readme.txt" + '\0' must fit.
+
+	char readme_path[MAX_PATH];
+	memcpy(readme_path, cfg->filename, prefix_length);
+	strecpy(readme_path + prefix_length, "readme.txt", lastof(readme_path));
+
+	TarFileList::iterator tar_entry = _tar_filelist.find(readme_path);
+	if (tar_entry == _tar_filelist.end()) return false;
+	return readme_path;
+}
+
+/**
+ * Load a readme.
+ * @param cfg The GRFConfig to load the readme from.
+ * @return the readme in char form.
+ */
+char *LoadReadme(const GRFConfig *cfg)
+{
+	char readme[MAX_README_LENGTH];
+	char readme_path = FindReadme(cfg);
+	return readme;
+}
+
 /**
  * Allocates and files a variable with the full path
  * based on the given directory.
diff -r c42a62268eee src/fileio_func.h
--- a/src/fileio_func.h	Fri Apr 29 18:35:36 2011 +0100
+++ b/src/fileio_func.h	Tue May 10 20:02:29 2011 +0100
@@ -13,6 +13,7 @@
 #define FILEIO_FUNC_H
 
 #include "fileio_type.h"
+#include "newgrf_config.h"
 
 void FioSeekTo(size_t pos, int mode);
 void FioSeekToFile(uint8 slot, size_t pos);
@@ -57,6 +58,9 @@
 
 void SanitizeFilename(char *filename);
 bool AppendPathSeparator(char *buf, size_t buflen);
+bool GrfHasReadme(const GRFConfig *cfg);
+char *FindReadme(const GRFConfig *cfg);
+char *LoadReadme(const GRFConfig *cfg);
 void DeterminePaths(const char *exe);
 void *ReadFileToMem(const char *filename, size_t *lenp, size_t maxsize);
 bool FileExists(const char *filename);
@@ -66,6 +70,8 @@
 
 extern char *_personal_dir; ///< custom directory for personal settings, saves, newgrf, etc.
 
+static const uint16 MAX_README_LENGTH = 8191;
+
 /** Helper for scanning for files with a given name */
 class FileScanner
 {
diff -r c42a62268eee src/lang/english.txt
--- a/src/lang/english.txt	Fri Apr 29 18:35:36 2011 +0100
+++ b/src/lang/english.txt	Tue May 10 20:02:29 2011 +0100
@@ -2384,6 +2384,7 @@
 STR_NEWGRF_SETTINGS_MOVEDOWN                                    :{BLACK}Move Down
 STR_NEWGRF_SETTINGS_MOVEDOWN_TOOLTIP                            :{BLACK}Move the selected NewGRF file down the list
 STR_NEWGRF_SETTINGS_FILE_TOOLTIP                                :{BLACK}A list of the NewGRF files that are installed. Click a file to change its parameters
+STR_NEWGRF_SETTINGS_VIEW_README                                 :{BLACK}View Readme
 
 STR_NEWGRF_SETTINGS_SET_PARAMETERS                              :{BLACK}Set parameters
 STR_NEWGRF_SETTINGS_TOGGLE_PALETTE                              :{BLACK}Toggle palette
@@ -2417,6 +2418,9 @@
 STR_NEWGRF_PARAMETERS_SETTING                                   :{STRING1}: {ORANGE}{STRING1}
 STR_NEWGRF_PARAMETERS_NUM_PARAM                                 :{LTBLUE}Number of parameters: {ORANGE}{NUM}
 
+# NewGRF readme window
+STR_NEWGRF_README_CAPTION                                       :{WHITE}View NewGRF Readme
+
 # NewGRF inspect window
 STR_NEWGRF_INSPECT_CAPTION                                      :{WHITE}Inspect - {STRING5}
 STR_NEWGRF_INSPECT_PARENT_BUTTON                                :{BLACK}Parent
diff -r c42a62268eee src/newgrf_gui.cpp
--- a/src/newgrf_gui.cpp	Fri Apr 29 18:35:36 2011 +0100
+++ b/src/newgrf_gui.cpp	Tue May 10 20:02:29 2011 +0100
@@ -25,6 +25,7 @@
 #include "core/geometry_func.hpp"
 #include "newgrf_text.h"
 #include "fileio_func.h"
+#include "tar_type.h"
 
 #include "table/strings.h"
 #include "table/sprites.h"
@@ -455,6 +456,110 @@
 	new NewGRFParametersWindow(&_newgrf_parameters_desc, c);
 }
 
+enum ShowNewGRFReadmeWidgets {
+	GRW_WIDGET_BACKGROUND,       ///< Panel to draw the readme on
+	GRW_WIDGET_SCROLLBAR,        ///< Scrollbar to scroll through the readme
+};
+
+struct NewGRFReadmeWindow : public Window {
+	GRFConfig *grf_config; ///< View the readme of this GRFConfig.
+	uint clicked_button;   ///< The row in which a button was clicked or UINT_MAX.
+	bool clicked_increase; ///< True if the increase button was clicked, false for the decrease button.
+	int timeout;           ///< How long before we unpress the last-pressed button?
+	int line_height;       ///< Height of a row in the matrix widget.
+	Scrollbar *vscroll;
+	
+	
+	static const int top_spacing;    ///< Additional spacing at the top of the #MHW_BACKGROUND widget.
+	static const int bottom_spacing; ///< Additional spacing at the bottom of the #MHW_BACKGROUND widget.
+
+	int date_width;  /// < Width needed for the date part.
+
+	NewGRFReadmeWindow(const WindowDesc *desc, GRFConfig *c) : Window(),
+		grf_config(c),
+		clicked_button(UINT_MAX),
+		timeout(0)
+	{
+		this->CreateNestedTree(desc);
+		this->vscroll = this->GetScrollbar(GRFPAR_WIDGET_SCROLLBAR);
+		this->FinishInitNested(desc);  // Initializes 'this->line_height' as side effect.
+		this->OnInvalidateData();
+	}
+
+	virtual void UpdateWidgetSize(int widget, Dimension *size, const Dimension &padding, Dimension *fill, Dimension *resize)
+	{
+		switch (widget) {
+			case GRW_WIDGET_BACKGROUND:
+				this->line_height = FONT_HEIGHT_NORMAL + 2;
+				resize->height = this->line_height;
+
+				size->height = 4 * resize->height + this->top_spacing + this->bottom_spacing; // At least 4 lines are visible.
+				size->width = max(200u, size->width); // At least 200 pixels wide.
+				break;
+		}
+	}
+
+	virtual void OnPaint()
+	{
+		this->OnInvalidateData(0);
+		this->DrawWidgets();
+	}
+
+	virtual void DrawWidget(const Rect &r, int widget) const
+	{
+		if (widget != GRW_WIDGET_BACKGROUND) return;
+	}
+
+	virtual void OnResize()
+	{
+	}
+
+	/**
+	 * Some data on this window has become invalid.
+	 * @param data Information about the changed data.
+	 * @param gui_scope Whether the call is done from GUI scope. You may not do everything when not in GUI scope. See #InvalidateWindowData() for details.
+	 */
+	virtual void OnInvalidateData(int data = 0, bool gui_scope = true)
+	{
+		if (!gui_scope) return;
+		DeleteChildWindows(WC_NEWGRF_README);
+	}
+};
+
+const int NewGRFReadmeWindow::top_spacing = WD_FRAMERECT_TOP + 4;
+const int NewGRFReadmeWindow::bottom_spacing = WD_FRAMERECT_BOTTOM;
+
+static const NWidgetPart _nested_newgrf_readme_widgets[] = {
+	NWidget(NWID_HORIZONTAL),
+		NWidget(WWT_CLOSEBOX, COLOUR_MAUVE),
+		NWidget(WWT_CAPTION, COLOUR_MAUVE), SetDataTip(STR_NEWGRF_README_CAPTION, STR_TOOLTIP_WINDOW_TITLE_DRAG_THIS),
+		NWidget(WWT_SHADEBOX, COLOUR_MAUVE),
+		NWidget(WWT_STICKYBOX, COLOUR_MAUVE),
+	EndContainer(),
+	NWidget(NWID_HORIZONTAL),
+		NWidget(WWT_PANEL, COLOUR_MAUVE, GRW_WIDGET_BACKGROUND), SetMinimalSize(200, 125), SetResize(1, 12), SetScrollbar(GRW_WIDGET_SCROLLBAR),
+		EndContainer(),
+		NWidget(NWID_VERTICAL),
+			NWidget(NWID_VSCROLLBAR, COLOUR_MAUVE, GRW_WIDGET_SCROLLBAR),
+			NWidget(WWT_RESIZEBOX, COLOUR_MAUVE),
+		EndContainer(),
+	EndContainer(),
+};
+
+/* Window definition for the grf readme window */
+static const WindowDesc _newgrf_readme_desc(
+	WDP_CENTER, 630, 460,
+	WC_NEWGRF_README, WC_NONE,
+	WDF_UNCLICK_BUTTONS,
+	_nested_newgrf_readme_widgets, lengthof(_nested_newgrf_readme_widgets)
+);
+
+void OpenNewGRFReadmeWindow(GRFConfig *c)
+{
+	DeleteWindowByClass(WC_NEWGRF_README);
+	new NewGRFReadmeWindow(&_newgrf_readme_desc, c);
+}
+
 static GRFPresetList _grf_preset_list;
 
 class DropDownListPresetItem : public DropDownListItem {
@@ -492,6 +597,7 @@
 	SNGRFS_SCROLL2BAR,
 	SNGRFS_NEWGRF_INFO_TITLE,
 	SNGRFS_NEWGRF_INFO,
+	SNGRFS_NEWGRF_README,
 	SNGRFS_SET_PARAMETERS,
 	SNGRFS_TOGGLE_PALETTE,
 	SNGRFS_APPLY_CHANGES,
@@ -570,6 +676,7 @@
 	~NewGRFWindow()
 	{
 		DeleteWindowByClass(WC_NEWGRF_PARAMETERS);
+		DeleteWindowByClass(WC_NEWGRF_README);
 
 		if (this->editable && !this->execute) {
 			CopyGRFConfigList(this->orig_list, this->actives, true);
@@ -936,6 +1043,18 @@
 				}
 				this->DeleteChildWindows(WC_QUERY_STRING); // Remove the parameter query window
 				break;
+			
+			case SNGRFS_NEWGRF_README: { // View GRF readme
+				if (this->active_sel == NULL && this->avail_sel == NULL) break;
+				
+				if (this->active_sel) {
+					OpenNewGRFReadmeWindow(this->active_sel);
+					break;
+				}
+				GRFConfig *c = new GRFConfig(*this->avail_sel);
+				OpenNewGRFReadmeWindow(c);
+				break;
+			}
 
 			case SNGRFS_SET_PARAMETERS: { // Edit parameters
 				if (this->active_sel == NULL || !this->editable || !this->show_params) break;
@@ -986,6 +1105,7 @@
 				this->avails.ForceRebuild();
 				this->InvalidateData(1);
 				this->DeleteChildWindows(WC_QUERY_STRING); // Remove the parameter query window
+				this->DeleteChildWindows(WC_NEWGRF_README); // Remove the view readme window
 				InvalidateWindowClassesData(WC_SAVELOAD);
 				break;
 		}
@@ -1102,6 +1222,13 @@
 			SNGRFS_MOVE_DOWN,
 			WIDGET_LIST_END
 		);
+
+		bool disable_readme = false;
+		if (this->avail_sel == NULL && this->active_sel == NULL) disable_readme = true;
+		const GRFConfig *c = (this->avail_sel == NULL ? this->active_sel : this->avail_sel);
+		if (!GrfHasReadme(c)) disable_readme = true;
+		this->SetWidgetDisabledState(SNGRFS_NEWGRF_README, disable_readme);
+
 		this->SetWidgetDisabledState(SNGRFS_SET_PARAMETERS, !this->show_params || disable_all);
 		this->SetWidgetDisabledState(SNGRFS_TOGGLE_PALETTE, disable_all);
 
@@ -1586,6 +1713,8 @@
 	NWidget(WWT_PANEL, COLOUR_MAUVE), SetPadding(0, 0, 2, 0),
 		NWidget(WWT_EMPTY, COLOUR_MAUVE, SNGRFS_NEWGRF_INFO_TITLE), SetFill(1, 0), SetResize(1, 0),
 		NWidget(WWT_EMPTY, COLOUR_MAUVE, SNGRFS_NEWGRF_INFO), SetFill(1, 1), SetResize(1, 1), SetMinimalSize(150, 100),
+		NWidget(WWT_PUSHTXTBTN, COLOUR_YELLOW, SNGRFS_NEWGRF_README), SetFill(1, 0), SetResize(1, 0),
+				SetDataTip(STR_NEWGRF_SETTINGS_VIEW_README, STR_NULL), SetPadding(2, 2, 2, 2), 
 	EndContainer(),
 	NWidget(NWID_SELECTION, INVALID_COLOUR, SNGRFS_SHOW_APPLY),
 		/* Right side, buttons. */
diff -r c42a62268eee src/window_type.h
--- a/src/window_type.h	Fri Apr 29 18:35:36 2011 +0100
+++ b/src/window_type.h	Tue May 10 20:02:29 2011 +0100
@@ -111,6 +111,7 @@
 	WC_INDUSTRY_CARGOES,
 	WC_NEWGRF_PARAMETERS,
 	WC_BUILD_OBJECT,
+	WC_NEWGRF_README,
 
 	WC_INVALID = 0xFFFF
 };