[groff] 11/25: [pic]: Fix "unused result" compiler warning.

[G. Branden Robinson]

gbranden pushed a commit to branch master
in repository groff.

commit caa10102c9f4333a471a7a1779319e5b18dcce52
Author: G. Branden Robinson <g.branden.robinson@gmail.com>
AuthorDate: Thu Feb 24 02:01:19 2022 +1100

    [pic]: Fix "unused result" compiler warning.
    
    * src/preproc/pic/pic.ypp (placeless_element) <SH>: Check return value
      of `system()` to quieten `-Wunused-result` warning; if it is less than
      zero, report it to the standard error stream.
    
    Also bump copyright year and add editor aid comments.
---
 ChangeLog               |  8 ++++++++
 src/preproc/pic/pic.ypp | 16 +++++++++++++---
 2 files changed, 21 insertions(+), 3 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 27f6c333..0dbb0971 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2022-02-24  G. Branden Robinson <g.branden.robinson@gmail.com>
+
+       [pic]: Fix "unused result" compiler warning.
+
+       * src/preproc/pic/pic.ypp (placeless_element) <SH>: Check return
+       value of `system()` to quieten `-Wunused-result` warning; if it
+       is less than zero, report it to the standard error stream.
+
 2022-02-23  G. Branden Robinson <g.branden.robinson@gmail.com>
 
        * tmac/safer.tmac: Drop file from distribution.  It contained
diff --git a/src/preproc/pic/pic.ypp b/src/preproc/pic/pic.ypp
index 0cbf556a..3fec08e9 100644
--- a/src/preproc/pic/pic.ypp
+++ b/src/preproc/pic/pic.ypp
@@ -1,4 +1,4 @@
-/* Copyright (C) 1989-2020 Free Software Foundation, Inc.
+/* Copyright (C) 1989-2022 Free Software Foundation, Inc.
      Written by James Clark (jjc@jclark.com)
 
 This file is part of groff.
@@ -360,8 +360,12 @@ placeless_element:
                  delim_flag = 0;
                  if (safer_flag)
                    lex_error("unsafe to run command '%1'", $3);
-                 else
-                   system($3);
+                 else {
+                   int retval = system($3);
+                   if (retval < 0)
+                     lex_error("error running command '%1': system()"
+                       " returned %2", $3, retval);
+                 }
                  delete[] $3;
                }
        | COPY TEXT
@@ -1934,3 +1938,9 @@ char *do_sprintf(const char *form, const double *v, int 
nv)
   result += '\0';
   return strsave(result.contents());
 }
+
+// Local Variables:
+// fill-column: 72
+// mode: C++
+// End:
+// vim: set cindent noexpandtab shiftwidth=2 textwidth=72: