[gnumeric] SUMIF: fix problems with blank criteria.

[Morten Welinder <mortenw src gnome org>]

commit 96c476dbc60b880e8a71132e3413867758380ca0
Author: Morten Welinder <terra gnome org>
Date:   Thu Oct 31 13:09:45 2019 -0400

    SUMIF: fix problems with blank criteria.

 ChangeLog      |  6 ++++++
 NEWS           |  1 +
 src/criteria.c | 30 ++++++++++++++++++++++++++++--
 3 files changed, 35 insertions(+), 2 deletions(-)
---
diff --git a/ChangeLog b/ChangeLog
index b4412130e..ec48b9156 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2019-10-31  Morten Welinder  <terra gnome org>
+
+       * src/criteria.c (parse_criteria): Be careful about critiria that
+       are either empty values or empty strings.  The semantics are
+       special.  [#423]  Fix initial ref-count problem.
+
 2019-09-19  Jean Brefort  <jean brefort normalesup org>
 
        * src/cell-draw.c (cell_calc_layout): implement wrapping of rotated text.
diff --git a/NEWS b/NEWS
index 4716e9145..6530db1d0 100644
--- a/NEWS
+++ b/NEWS
@@ -14,6 +14,7 @@ Morten:
        * Fix inter-process paste crash [#406]
        * Fix problem saving cell protection to xlsx.  [#409]
        * Look for python3 before python.  [#419]
+       * Fix SUMIF (etc) problem with blank criteria.  [#423]
 
 --------------------------------------------------------------------------
 Gnumeric 1.12.45
diff --git a/src/criteria.c b/src/criteria.c
index 1e297b975..a41245440 100644
--- a/src/criteria.c
+++ b/src/criteria.c
@@ -203,12 +203,28 @@ criteria_test_empty (GnmValue const *x, GnmCriteria *crit)
        return VALUE_IS_EMPTY (x);
 }
 
+static gboolean
+criteria_test_blank (GnmValue const *x, GnmCriteria *crit)
+{
+       if (VALUE_IS_EMPTY (x))
+               return TRUE;
+       if (!VALUE_IS_STRING (x))
+               return FALSE;
+       return *value_peek_string (x) == 0;
+}
+
 static gboolean
 criteria_test_nonempty (GnmValue const *x, GnmCriteria *crit)
 {
        return !VALUE_IS_EMPTY (x);
 }
 
+static gboolean
+criteria_test_nothing (GnmValue const *x, GnmCriteria *crit)
+{
+       return FALSE;
+}
+
 /*
  * Finds a column index of a field.
  */
@@ -345,6 +361,7 @@ parse_criteria (GnmValue const *crit_val, GODateConventions const *date_conv,
 
        res->iter_flags = CELL_ITER_IGNORE_BLANK;
        res->date_conv = date_conv;
+       res->ref_count = 1;
 
        if (VALUE_IS_NUMBER (crit_val)) {
                res->fun = criteria_test_equal;
@@ -352,8 +369,18 @@ parse_criteria (GnmValue const *crit_val, GODateConventions const *date_conv,
                return res;
        }
 
+       if (VALUE_IS_EMPTY (crit_val)) {
+               // Empty value
+               res->fun = criteria_test_nothing;
+               res->x = value_new_empty ();
+               return res;
+       }
+
        criteria = value_peek_string (crit_val);
-        if (strncmp (criteria, "<=", 2) == 0) {
+       if (*criteria == 0) {
+               res->fun = criteria_test_blank;
+               len = 0;
+       } else if (strncmp (criteria, "<=", 2) == 0) {
                res->fun = criteria_test_less_or_equal;
                len = 2;
        } else if (strncmp (criteria, ">=", 2) == 0) {
@@ -389,7 +416,6 @@ parse_criteria (GnmValue const *crit_val, GODateConventions const *date_conv,
        if (res->fun (empty, res))
                res->iter_flags &= ~CELL_ITER_IGNORE_BLANK;
        value_release (empty);
-       res->ref_count = 1;
 
        return res;
 }