ncmpidiff/ncdiff - add xfail test when 2 input file names are identical

Author: wkliao

.gitignore

@@ -83,6 +83,7 @@ Makefile
 *.nc1
 *.nc2
 *.nc5
+!/src/utils/ncmpidiff/tst_file.nc
 !/src/utils/ncvalidator/bad_*.nc
 !/src/utils/ncvalidator/bad_*.nc?
 !/test/cdf_format/bad_*.nc?

src/utils/ncmpidiff/Makefile.am

@@ -11,6 +11,8 @@ AM_CPPFLAGS += -I$(top_builddir)/src/include
 
 bin_PROGRAMS = ncmpidiff cdfdiff
 
+check_PROGRAMS = $(bin_PROGRAMS)
+
 noinst_LTLIBRARIES = libncmpidiff_core.la
 libncmpidiff_core_la_SOURCES = ncmpidiff_core.c
 
@@ -28,7 +30,20 @@ $(top_builddir)/src/libs/libpnetcdf.la:
 
 dist_man_MANS = ncmpidiff.1 cdfdiff.1
 
-EXTRA_DIST = ncmpidiff_core.h
+AM_TESTS_ENVIRONMENT  = export check_PROGRAMS="$(check_PROGRAMS)";
+AM_TESTS_ENVIRONMENT += export SED="$(SED)";
+AM_TESTS_ENVIRONMENT += export srcdir="$(srcdir)";
+AM_TESTS_ENVIRONMENT += export TESTOUTDIR="$(FSTYPE_PREFIX)$(TESTOUTDIR)";
+AM_TESTS_ENVIRONMENT += export TESTSEQRUN="$(TESTSEQRUN)";
+AM_TESTS_ENVIRONMENT += export TESTMPIRUN="$(TESTMPIRUN)";
+
+TESTS = $(check_PROGRAMS)
+XFAIL_TESTS = $(check_PROGRAMS)
+EST_EXTENSIONS = .sh
+LOG_COMPILER = $(srcdir)/xfail_runs.sh
+SH_LOG_COMPILER =
+
+EXTRA_DIST = ncmpidiff_core.h tst_file.nc
 
 CLEANFILES = core core.* *.gcda *.gcno *.gcov gmon.out
 

src/utils/ncmpidiff/cdfdiff.c

@@ -309,6 +309,12 @@ int main(int argc, char **argv)
 
     if (argc - optind != 2) usage(argv[0]);
 
+    if (strcmp(argv[optind], argv[optind+1]) == 0) {
+        printf("Error: two input file names are identical (%s) ... exit\n",
+               argv[optind]);
+        exit(1);
+    }
+
     if (verbose && check_tolerance) {
         printf("Tolerance absolute difference = %e\n", tolerance_difference);
         printf("Tolerance ratio    difference = %e\n", tolerance_ratio);

src/utils/ncmpidiff/tst_file.nc

@@ -0,0 +1,38 @@
+#!/bin/bash
+#
+# Copyright (C) 2026, Northwestern University and Argonne National Laboratory
+# See COPYRIGHT notice in top-level directory.
+#
+
+# Exit immediately if a command exits with a non-zero status.
+set -e
+
+DRY_RUN=no
+VERBOSE=yes
+
+if test "x$1" = "x./ncmpidiff" ; then
+   RUN_CMD=`echo ${TESTMPIRUN} | ${SED} -e "s/NP/4/g"`
+else
+   RUN_CMD=$TESTSEQRUN
+fi
+
+run_cmd() {
+   local lineno=${BASH_LINENO[$((${#BASH_LINENO[@]} - 2))]}
+   if test "x$VERBOSE" = xyes || test "x$DRY_RUN" = xyes ; then
+      echo "Line $lineno CMD: $RUN_CMD $@"
+   fi
+   if test "x$DRY_RUN" = xno ; then
+      $RUN_CMD $@
+   fi
+}
+
+exe_name=`basename $1`
+
+# prevent user environment setting of PNETCDF_HINTS to interfere
+unset PNETCDF_HINTS
+
+# ncmpidiff/ncdiff should error out when two input file names are identical.
+IDENT_FILE=${srcdir}/tst_file.nc
+
+run_cmd $1 ${IDENT_FILE} ${IDENT_FILE}
+