Patch from John, update man page.

3 files changed, 41 insertions, 6 deletions

diff --git a/ChangeLog b/ChangeLog
index 5fcbb96e..ed69432b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+Sun Apr 24 12:43:49 2011  John Haque      <j.eh@mchsi.com>
+
+	* array.c (sort_user_func): Fix return value to match the
+	documentaion.
+	(sort_selection): Make user-specified comparison function with
+	the same name override default "unsorted" specification.
+
 Fri Apr 22 16:05:27 2011  John Haque      <j.eh@mchsi.com>
 
 	* array.c (sort_user_func): New routine to handle user-defined
diff --git a/array.c b/array.c
index 32b85065..1bf6a068 100644
--- a/array.c
+++ b/array.c
@@ -1371,8 +1371,8 @@ static int
 sort_user_func(const void *p1, const void *p2)
 {
 	const NODE *t1, *t2;
-	NODE *idx1, *idx2, *val1, *val2, *r;
-	int ret;
+	NODE *idx1, *idx2, *val1, *val2;
+	AWKNUM ret;
 	INSTRUCTION *code;
 	extern int exiting;
 
@@ -1403,11 +1403,9 @@ sort_user_func(const void *p1, const void *p2)
 		gawk_exit(exit_val);
 
 	/* return value of the comparison function */
-	r = POP_SCALAR();
-	ret = (int) force_number(r);
-	DEREF(r);
+	POP_NUMBER(ret);
 
-	return ret;
+	return (ret < 0.0) ? -1 : (ret > 0.0);
 }
 
 
@@ -1522,6 +1520,14 @@ sort_selection(NODE *sort_str, SORT_CTXT sort_ctxt)
 		allparts |= bval;
 	}
 
+	if (allparts == Unsorted) {
+		NODE *f;
+		/* user-defined function overrides default */
+
+		if ((f = lookup(sort_str->stptr)) != NULL && f->type == Node_func)
+			return -1;
+	}
+
 	/* num_words <= 3 */
 	return (allparts & INDEX_MASK);
 
diff --git a/doc/gawk.1 b/doc/gawk.1
index 629899b1..3fdf5605 100644
--- a/doc/gawk.1
+++ b/doc/gawk.1
@@ -1098,6 +1098,25 @@ Supported values are
 \fB"unsorted"\fR.
 The order specification words can be truncated, or omitted (provided
 that at least one is present), or given in any order.
+The value can also be the name of any comparison function defined
+as follows:
+.PP
+.RS
+\fBfunction cmp_func(i1, v1, i2, v2)\fR
+.RE
+.PP
+where
+.I i1
+and
+.I i2
+are the indices, and
+.I v1
+and
+.I v2
+are the
+corresponding values of the two elements being compared.
+It should return a number less than, equal to, or greater than 0,
+depending on how the elements of the array are to be ordered.
 .TP
 \fBPROCINFO["version"]\fP
 the version of
@@ -2475,6 +2494,9 @@ Valid values for
 .I how
 are "ascending string", "ascending number",
 "descending string" and "descending number".
+It can also be the name of a user-defined
+comparison function as described in
+\fBPROCINFO["sorted_in"]\fR.
 .TP "\w'\fBsprintf(\^\fIfmt\fB\^, \fIexpr-list\^\fB)\fR'u+1n"
 \fBasorti(\fIs \fR[\fB, \fId\fR [\fB, \fIhow\fR] ]\fB)\fR
 Return the number of elements in the source