From 4ed49d2f21ffe6a65d022d46906ff9c82ec1ec7a Mon Sep 17 00:00:00 2001
From: Axel Kohlmeyer <akohlmey@gmail.com>
Date: Tue, 7 Mar 2023 13:44:34 -0500
Subject: [PATCH] make Input::file(const char *) function safe for passing a
 null pointer

---
 src/input.cpp   | 23 ++++++++++++-----------
 src/library.cpp |  3 +--
 2 files changed, 13 insertions(+), 13 deletions(-)

diff --git a/src/input.cpp b/src/input.cpp
index e653704ae3..ef0433dc99 100644
--- a/src/input.cpp
+++ b/src/input.cpp
@@ -327,15 +327,14 @@ void Input::file(const char *filename)
   // call to file() will close filename and decrement nfile
 
   if (me == 0) {
-    if (nfile == maxfile)
-      error->one(FLERR,"Too many nested levels of input scripts");
+    if (nfile == maxfile) error->one(FLERR,"Too many nested levels of input scripts");
 
-    infile = fopen(filename,"r");
-    if (infile == nullptr)
-      error->one(FLERR,"Cannot open input script {}: {}",
-                                   filename, utils::getsyserror());
-
-    infiles[nfile++] = infile;
+    if (filename) {
+      infile = fopen(filename,"r");
+      if (infile == nullptr)
+        error->one(FLERR,"Cannot open input script {}: {}", filename, utils::getsyserror());
+      infiles[nfile++] = infile;
+    }
   }
 
   // process contents of file
@@ -343,9 +342,11 @@ void Input::file(const char *filename)
   file();
 
   if (me == 0) {
-    fclose(infile);
-    nfile--;
-    infile = infiles[nfile-1];
+    if (filename) {
+      fclose(infile);
+      nfile--;
+      infile = infiles[nfile-1];
+    }
   }
 }
 
diff --git a/src/library.cpp b/src/library.cpp
index 7fcc22ef17..9f817a1199 100644
--- a/src/library.cpp
+++ b/src/library.cpp
@@ -532,8 +532,7 @@ void lammps_file(void *handle, const char *filename)
   BEGIN_CAPTURE
   {
     if (lmp->update->whichflag != 0)
-      lmp->error->all(FLERR,"Library error: issuing LAMMPS commands "
-                      "during a run is not allowed.");
+      lmp->error->all(FLERR, "Library error: issuing LAMMPS commands during a run is not allowed");
     else
       lmp->input->file(filename);
   }