[LyX/master] Properly resolve crossref'ed data in BiblioInfo

[Juergen Spitzmueller]

commit 5b11066a3787bc136b0a5bb6ba34e67af51ccd89
Author: Juergen Spitzmueller <spitz at lyx.org>
Date:   Sat Feb 24 15:26:41 2024 +0100

    Properly resolve crossref'ed data in BiblioInfo
    
    This needs to take the mappings into account as well, not just
    plain fields.
---
 src/BiblioInfo.cpp | 24 +++++++++++++++---------
 1 file changed, 15 insertions(+), 9 deletions(-)

diff --git a/src/BiblioInfo.cpp b/src/BiblioInfo.cpp
index 63eb2f2263..cb340d4c89 100644
--- a/src/BiblioInfo.cpp
+++ b/src/BiblioInfo.cpp
@@ -1137,15 +1137,6 @@ docstring BibTeXInfo::getValueForKey(string const & oldkey, Buffer const & buf,
 	}
 
 	docstring ret = operator[](key);
-	if (ret.empty() && !xrefs.empty()) {
-		// xr is a (reference to a) BibTeXInfo const *
-		for (auto const & xr : xrefs) {
-			if (xr && !(*xr)[key].empty()) {
-				ret = (*xr)[key];
-				break;
-			}
-		}
-	}
 	if (ret.empty()) {
 		// some special keys
 		// FIXME: dialog, textbefore and textafter have nothing to do with this
@@ -1283,6 +1274,21 @@ docstring BibTeXInfo::getValueForKey(string const & oldkey, Buffer const & buf,
 			ret = getYear();
 	}
 
+	// If we have no result, check in the cross-ref'ed entries
+	if (ret.empty() && !xrefs.empty()) {
+		// xr is a (reference to a) BibTeXInfo const *
+		for (auto const & xr : xrefs) {
+			if (!xr)
+				continue;
+			// use empty BibTeXInfoList to avoid loops
+			BibTeXInfoList xr_dummy;
+			ret = xr->getValueForKey(oldkey, buf, ci, xr_dummy, maxsize);
+			if (!ret.empty())
+				// success!
+				break;
+		}
+	}
+
 	if (cleanit)
 		ret = xml::cleanAttr(ret);