fix: regression that truncates error message when offset is out of bounds

- Happens when offset > the number of rows and when "Prefer: count=exact" header is sent
- Regression introduced in commit 57ef998

CHANGELOG.md

@@ -10,6 +10,9 @@ All notable changes to this project will be documented in this file. From versio
 
 ## [14.1] - 2025-11-05
 
+- Fix regression where the `PGRST103` error response was truncated by @laurenceisla in #4455
+  + Happened when an `offset` was greater than the rows requested and `Prefer: count=exact` was sent.
+
 ## Fixed
 
 - Fix `db-pre-config` function failing when function names are pg reserved words by @taimoorzaeem in #4380

src/PostgREST/Response.hs

@@ -65,7 +65,7 @@ actionResponse :: DbResult -> ApiRequest -> (Text, Text) -> AppConfig -> SchemaC
 actionResponse (DbCrudResult WrappedReadPlan{pMedia, wrHdrsOnly=headersOnly, crudQi=identifier} RSStandard{..}) ctxApiRequest@ApiRequest{iPreferences=Preferences{..},..} _ _ _ _ _ = do
   let
     (status, contentRange) = RangeQuery.rangeStatusHeader iTopLevelRange rsQueryTotal rsTableTotal
-    cLHeader = if headersOnly then mempty else [contentLengthHeaderStrict rsBody]
+    cLHeader = if headersOnly then mempty else [contentLengthHeaderLazy bod]
     prefHeader = maybeToList . prefAppliedHeader $ Preferences Nothing Nothing preferCount preferTransaction Nothing preferHandling preferTimezone Nothing []
     headers =
       [ contentRange

test/spec/Feature/Query/RangeSpec.hs

@@ -126,7 +126,8 @@ spec = do
                 "hint":null
               }|]
             { matchStatus  = 416
-            , matchHeaders = ["Content-Range" <:> "*/0"]
+            , matchHeaders = [ "Content-Range" <:> "*/0"
+                             , "Content-Length" <:> "144"]
             }
 
         it "refuses a range requesting start past last item" $
@@ -288,7 +289,8 @@ spec = do
                 "hint":null
               }|]
             { matchStatus  = 416
-            , matchHeaders = ["Content-Range" <:> "*/0"]
+            , matchHeaders = [ "Content-Range" <:> "*/0"
+                             , "Content-Length" <:>  "144"]
             }
 
         it "refuses a range requesting start past last item" $
@@ -470,7 +472,8 @@ spec = do
                 "hint":null
               }|]
             { matchStatus  = 416
-            , matchHeaders = ["Content-Range" <:> "*/0"]
+            , matchHeaders = [ "Content-Range" <:> "*/0"
+                             , "Content-Length" <:> "144"]
             }
 
         it "refuses a range requesting start past last item" $