Introduce errors-show

a way to re-open the (LaTeX or other processing) errors dialog after it
had been closed without having to re-compile the document (#2775)

lib/RELEASE-NOTES

@@ -17,6 +17,9 @@
 
 !!!The following new LyX functions have been introduced in 2.5:
 
+- The new function show-errors re-displays the (e.g., LaTeX) errors dialog 
+  if there had been any processing errors.
+
 - The new function word-invertcase is a companion of word-upcase and
   word-lowcase: it inverts each character between lowcase and upcase,
   which is useful when one FORGOT THE cAPS lOCK KEY.

lib/ui/stdmenus.inc

@@ -575,6 +575,7 @@ Menuset
 		Submenu "Change Tracking|C" "document_change"
 		OptItem "Build Program|B" "build-program"
 		Item "LaTeX Log|L" "dialog-show latexlog"
+		Item "Processing Errors|r" "errors-show"
 		Item "Start Appendix Here|x" "appendix"
 		Separator
 		ViewFormats

src/FuncCode.h

@@ -513,6 +513,7 @@ enum FuncCode
 	// 400
 	LFUN_REFERENCE_TO_PARAGRAPH,    // spitz, 20240728
 	LFUN_WORD_INVERTCASE,           // lasgouttes 20241015
+	LFUN_ERRORS_SHOW,               // spitz 20241231
 	LFUN_LASTACTION                 // end of the table
 };
 

src/LyXAction.cpp

@@ -1579,6 +1579,14 @@ void LyXAction::init()
  */
 		{ LFUN_ENVIRONMENT_SPLIT, "environment-split", Noop, Layout },
 
+/*!
+ * \var lyx::FuncCode lyx::LFUN_ERRORS_SHOW
+ * \li Action: Shows export error dialog if errors exist.
+ * \li Syntax: errors-show
+ * \li Origin: spitz, 31 Dec 2024
+ * \endvar
+ */
+		{ LFUN_ERRORS_SHOW, "errors-show", NoBuffer, Edit },
 
 /*!
  * \var lyx::FuncCode lyx::LFUN_ERT_INSERT

src/frontends/qt/GuiView.cpp

@@ -2673,6 +2673,12 @@ bool GuiView::getStatus(FuncRequest const & cmd, FuncStatus & flag)
 		break;
 	}
 
+	case LFUN_ERRORS_SHOW: {
+		enable = buf && (!buf->errorList(d.last_export_format).empty()
+				 || !buf->masterBuffer()->errorList(d.last_export_format).empty());
+		break;
+	}
+
 	case LFUN_COMMAND_EXECUTE:
 	case LFUN_MESSAGE:
 	case LFUN_MENU_OPEN:
@@ -4916,6 +4922,13 @@ void GuiView::dispatch(FuncRequest const & cmd, DispatchResult & dr)
 			break;
 		}
 
+		case LFUN_ERRORS_SHOW: {
+			// We guess it's from master if the single buffer list is empty
+			bool const from_master = bv->buffer().errorList(d.last_export_format).empty();
+			errors(d.last_export_format, from_master);
+			break;
+		}
+
 		case LFUN_MESSAGE:
 			dr.setMessage(cmd.argument());
 			break;