[SV 58497] Ensure $(file <) newline removal succeeds

Keep a count of bytes read rather than comparing pointers since the
variable_buffer might get reallocated.

Bug and patch by Ken Tossell <ken@tossell.net>
Regression tests by Dmitry Goncharov <dgoncharov@users.sf.net>
Tweaked by Paul Smith <psmith@gnu.org>

* src/function.c (func_file): Use bytes read rather than a pointer.
* tests/scripts/functions/file: Provide various tests for reading
empty files, files with/without newlines, and large files.

1 files changed, 6 insertions, 1 deletions

diff --git a/tests/thelp.pl b/tests/thelp.pl
index d8aaa667..ed8c819e 100755
--- a/tests/thelp.pl
+++ b/tests/thelp.pl
@@ -8,7 +8,8 @@
 # Each step consists of an operator and argument.
 #
 # It supports the following operators:
-#  out <word>   : echo <word> to stdout
+#  out <word>   : echo <word> to stdout with a newline
+#  raw <word>   : echo <word> to stdout without adding anything
 #  file <word>  : echo <word> to stdout AND create the file <word>
 #  dir <word>   : echo <word> to stdout AND create the directory <word>
 #  rm <word>    : echo <word> to stdout AND delete the file/directory <word>
@@ -34,6 +35,10 @@ sub op {
         print "$nm\n";
         return 1;
     }
+    if ($op eq 'raw') {
+        print "$nm";
+        return 1;
+    }
 
     # Show the output before creating the file
     if ($op eq 'file') {