Fix show of SparseAxisArray for small display size (#3996)

Author: blegat

src/Containers/SparseAxisArray.jl

@@ -467,7 +467,7 @@ function Base.show(io::IOContext, x::SparseAxisArray)
         (i, (key, value)) in enumerate(x.data) if
         i < half_screen_rows || i > length(x) - half_screen_rows
     ]
-    pad = maximum(length(x[1]) for x in key_strings)
+    pad = maximum((length(x[1]) for x in key_strings); init = 0)
     for (i, (key, value)) in enumerate(key_strings)
         print(io, "  [", rpad(key, pad), "]  =  ", value)
         if i != length(key_strings)

test/Containers/test_SparseAxisArray.jl

@@ -395,4 +395,14 @@ function test_empty_vector_indices()
     return
 end
 
+function test_small_displaysize()
+    for row in 0:9
+        d = Containers.container(+, [(1, 2)], Containers.SparseAxisArray)
+        io = IOContext(IOBuffer(), :limit => true, :displaysize => (row, 80))
+        show(io, d)
+        @test String(take!(io.io)) == ""
+    end
+    return
+end
+
 end  # module