From 22348efd905fa8e3b5c30448fd0e2787056b2d5f Mon Sep 17 00:00:00 2001
From: Joseph Wright <joseph.wright@morningstar2.co.uk>
Date: Mon, 11 Sep 2023 10:19:25 +0100
Subject: [PATCH] Return passing errorlevel if BibTeX issues warnings (fixes
 #260)

---
 CHANGELOG.md            | 4 ++++
 l3build-typesetting.lua | 6 ++++--
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 45a1038b..5ba802a7 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -14,6 +14,10 @@ this project uses date-based 'snapshot' version identifiers.
 - Extend version string normalisation during checks
   (see issue \#96)
 
+### Fixed
+- Return passing errorlevel if BibTeX issues warnings
+  (see \#260)
+
 ## [2023-09-07]
 
 ### Changed
diff --git a/l3build-typesetting.lua b/l3build-typesetting.lua
index d0e491d4..c12c5447 100644
--- a/l3build-typesetting.lua
+++ b/l3build-typesetting.lua
@@ -72,8 +72,10 @@ function bibtex(name,dir)
         os_grepexe .. " \"^" .. grep .. "bibdata{\" " .. name .. ".aux > "
           .. os_null
       ) == 0 then
-      return runcmd(bibtexexe .. " " .. bibtexopts .. " " .. name,dir,
-        {"BIBINPUTS","BSTINPUTS"})
+      local errorlevel = runcmd(bibtexexe .. " " .. bibtexopts .. " " .. name,
+        dir,{"BIBINPUTS","BSTINPUTS"})
+      -- BibTeX(8) signals warnings with errorlevel 1
+      if errorlevel > 1 then return errorlevel else return 0 end
     end
   end
   return 0