truncate: ignore whitespace in --size parameters

Without this, `truncate -s '> -1' F` would truncate F to length 0,
and `truncate -s " +1" F` would truncate F to 1 byte.  Now, each
elicits a diagnostic.
* src/truncate.c: Skip leading white space in the --size option
argument and any white space after one of the relative modifiers,
so that the presence of a +/- modifier can be detected reliably.
* tests/misc/truncate-parameters: Add tests for the above.

2 files changed, 12 insertions, 0 deletions

diff --git a/src/truncate.c b/src/truncate.c
index fd321c6c5..3bc52ca14 100644
--- a/src/truncate.c
+++ b/src/truncate.c
@@ -286,6 +286,9 @@ main (int argc, char **argv)
           break;
 
         case 's':
+          /* skip any whitespace */
+          while (isspace (*optarg))
+            optarg++;
           switch (*optarg)
             {
             case '<':
@@ -305,6 +308,9 @@ main (int argc, char **argv)
               optarg++;
               break;
             }
+          /* skip any whitespace */
+          while (isspace (*optarg))
+            optarg++;
           if (*optarg == '+' || *optarg == '-')
             {
               if (rel_mode)
diff --git a/tests/misc/truncate-parameters b/tests/misc/truncate-parameters
index e41683190..27a22a91f 100755
--- a/tests/misc/truncate-parameters
+++ b/tests/misc/truncate-parameters
@@ -40,4 +40,10 @@ truncate --io-blocks --reference=file file && fail=1
 # must specify valid numbers
 truncate --size="invalid" file && fail=1
 
+# spaces not significant around size
+truncate --size="> -1" file && fail=1
+truncate --size=" >1" file || fail=1 #file now 1
+truncate --size=" +1" file || fail=1 #file now 2
+test $(stat --format %s file) = 2 || fail=1
+
 (exit $fail); exit $fail