[FileFormats.NL] ignore, rather than error, when names are given (#2390)

Author: odow

src/FileFormats/NL/NL.jl

@@ -548,6 +548,8 @@ function Base.write(io::IO, model::Model)
     # Line 1: Always the same
     # Notes:
     #  * I think these are magic bytes used by AMPL internally for stuff.
+    #  * The first "1" is if the next row includes the number of logical
+    #    constraints.
     println(io, "g3 1 1 0")
 
     # Line 2: vars, constraints, objectives, ranges, eqns, logical constraints

src/FileFormats/NL/read.jl

@@ -312,9 +312,8 @@ function _parse_header(io::IO, model::_CacheModel)
     @assert _next(Int, io, model) >= 0
     _read_til_newline(io)
     # Line 9
-    # We don't support reading variable and constraint names
-    @assert _next(Int, io, model) == 0
-    @assert _next(Int, io, model) == 0
+    # We don't support reading variable and constraint names, so just ignore
+    # them
     _read_til_newline(io)
     # Line 10
     # We don't support reading common subexpressions

test/FileFormats/NL/read.jl

@@ -150,8 +150,6 @@ function test_parse_header_assertion_errors()
         "g3 1 1 0\n4 2 1 0 1 0\n2 1\n0 0\n4 0 0\n0 0 1 1\n",
         "g3 1 1 0\n4 2 1 0 1 0\n2 1\n0 0\n4 0 0\n0 0 0 1\n0 0 0 2 0\n-1 0\n",
         "g3 1 1 0\n4 2 1 0 1 0\n2 1\n0 0\n4 0 0\n0 0 0 1\n0 0 0 2 0\n0 -1\n",
-        "g3 1 1 0\n4 2 1 0 1 0\n2 1\n0 0\n4 0 0\n0 0 0 1\n0 0 0 2 0\n8 4\n1 0\n",
-        "g3 1 1 0\n4 2 1 0 1 0\n2 1\n0 0\n4 0 0\n0 0 0 1\n0 0 0 2 0\n8 4\n0 1\n",
     ]
         io = IOBuffer()
         write(io, header)