[gnumeric] DCOUNT/DCOUNTA: Allow missing field argument.

[Morten Welinder <mortenw src gnome org>]

commit 19044f4bef1007b84b4b43f5f5b679e544afb30e
Author: Morten Welinder <terra gnome org>
Date:   Thu Jun 9 14:34:04 2016 -0400

    DCOUNT/DCOUNTA: Allow missing field argument.

 NEWS                            |    1 +
 plugins/fn-database/ChangeLog   |   11 +++++++
 plugins/fn-database/functions.c |   58 ++++++++++++++++++++++++++++-----------
 src/value.c                     |    2 +-
 4 files changed, 55 insertions(+), 17 deletions(-)
---
diff --git a/NEWS b/NEWS
index 5de164c..4de3fc1 100644
--- a/NEWS
+++ b/NEWS
@@ -2,6 +2,7 @@ Gnumeric 1.12.30
 
 Morten:
        * Improve format guessing for csv and txt files.
+       * Fix DCOUNT and DCOUNTA with missing field.  [#767290]
 
 --------------------------------------------------------------------------
 Gnumeric 1.12.29
diff --git a/plugins/fn-database/ChangeLog b/plugins/fn-database/ChangeLog
index a976e70..ce22faa 100644
--- a/plugins/fn-database/ChangeLog
+++ b/plugins/fn-database/ChangeLog
@@ -1,3 +1,14 @@
+2016-06-09  Morten Welinder  <terra gnome org>
+
+       * functions.c (database_find_values): Accept also
+       COLLECT_IGNORE_ERRORS.
+       (gnumeric_dcount): Use database_value_range_function; ignore
+       errors.
+       (gnumeric_dcounta): Use database_value_range_function.
+       (database_value_range_function): Add flag to control whether a
+       missing field is allowed.  Clear all flags in that case.
+       (find_cells_that_match): Handle missing field.  Poorly.
+
 2016-05-06  Morten Welinder <terra gnome org>
 
        * Release 1.12.29
diff --git a/plugins/fn-database/functions.c b/plugins/fn-database/functions.c
index 308951e..f14bb5b 100644
--- a/plugins/fn-database/functions.c
+++ b/plugins/fn-database/functions.c
@@ -102,19 +102,23 @@ find_cells_that_match (Sheet *sheet, GnmValue const *database,
        int    row, first_row, last_row;
        gboolean add_flag;
        GnmCell *cell;
+       int fake_col;
 
        cells = NULL;
        /* TODO : Why ignore the first row ?  What if there is no header ? */
        first_row = database->v_range.cell.a.row + 1;
        last_row  = database->v_range.cell.b.row;
+       fake_col = database->v_range.cell.a.col;
 
        for (row = first_row; row <= last_row; row++) {
-               cell = sheet_cell_get (sheet, col, row);
+               cell = (col == -1)
+                       ? sheet_cell_fetch (sheet, fake_col, row)
+                       : sheet_cell_get (sheet, col, row);
 
                if (cell != NULL)
                        gnm_cell_eval (cell);
 
-               if (gnm_cell_is_empty (cell))
+               if (col != -1 && gnm_cell_is_empty (cell))
                        continue;
 
                add_flag = TRUE;
@@ -161,14 +165,17 @@ database_find_values (Sheet *sheet, GnmValue const *database,
        GnmValue **res2 = NULL;
        void *res;
 
-       if (flags & ~(COLLECT_IGNORE_STRINGS | COLLECT_IGNORE_BOOLS | COLLECT_IGNORE_BLANKS)) {
+       if (flags & ~(COLLECT_IGNORE_STRINGS |
+                     COLLECT_IGNORE_BOOLS |
+                     COLLECT_IGNORE_BLANKS |
+                     COLLECT_IGNORE_ERRORS)) {
                g_warning ("unsupported flags in database_find_values %x", flags);
        }
 
        /* FIXME: expand and sanitise this call later.  */
        cells = find_cells_that_match (sheet, database, col, criterias);
-
        cellcount = g_slist_length (cells);
+
        /* Allocate memory -- one extra to make sure we don't get NULL.  */
        if (floats)
                res = res1 = g_new (gnm_float, cellcount + 1);
@@ -184,6 +191,8 @@ database_find_values (Sheet *sheet, GnmValue const *database,
                        continue;
                if ((flags & COLLECT_IGNORE_BLANKS) && VALUE_IS_EMPTY (value))
                        continue;
+               if ((flags & COLLECT_IGNORE_ERRORS) && VALUE_IS_ERROR (value))
+                       continue;
                if (floats)
                        res1[count++] = value_get_as_float (value);
                else
@@ -270,7 +279,8 @@ database_value_range_function (GnmFuncEvalInfo *ei,
                               value_range_function_t func,
                               CollectFlags flags,
                               GnmStdError zero_count_error,
-                              GnmStdError func_error)
+                              GnmStdError func_error,
+                              gboolean allow_missing_field)
 {
        int fieldno;
        GSList *criterias = NULL;
@@ -285,9 +295,14 @@ database_value_range_function (GnmFuncEvalInfo *ei,
            !VALUE_IS_CELLRANGE (database))
                return value_new_error_NUM (ei->pos);
 
-       fieldno = find_column_of_field (ei->pos, database, field);
-       if (fieldno < 0)
-               return value_new_error_NUM (ei->pos);
+       if (allow_missing_field && VALUE_IS_EMPTY (field)) {
+               flags = 0;
+               fieldno = -1;
+       } else {
+               fieldno = find_column_of_field (ei->pos, database, field);
+               if (fieldno < 0)
+                       return value_new_error_NUM (ei->pos);
+       }
 
        criterias = parse_database_criteria (ei->pos, database, criteria);
        if (criterias == NULL)
@@ -374,20 +389,29 @@ static GnmFuncHelp const help_dcount[] = {
        { GNM_FUNC_HELP_END }
 };
 
+static int
+range_count (G_GNUC_UNUSED GnmValue **xs, int n, GnmValue **res)
+{
+       *res = value_new_int (n);
+       return 0;
+}
+
 
 static GnmValue *
 gnumeric_dcount (GnmFuncEvalInfo *ei, GnmValue const * const *argv)
 {
-       return database_float_range_function (ei,
+       return database_value_range_function (ei,
                                              argv[0],
                                              argv[1],
                                              argv[2],
-                                             gnm_range_count,
+                                             range_count,
                                              COLLECT_IGNORE_STRINGS |
                                              COLLECT_IGNORE_BOOLS |
-                                             COLLECT_IGNORE_BLANKS,
+                                             COLLECT_IGNORE_BLANKS |
+                                             COLLECT_IGNORE_ERRORS,
                                              GNM_ERROR_UNKNOWN,
-                                             GNM_ERROR_NUM);
+                                             GNM_ERROR_NUM,
+                                             TRUE);
 }
 
 /***************************************************************************/
@@ -412,14 +436,15 @@ static GnmFuncHelp const help_dcounta[] = {
 static GnmValue *
 gnumeric_dcounta (GnmFuncEvalInfo *ei, GnmValue const * const *argv)
 {
-       return database_float_range_function (ei,
+       return database_value_range_function (ei,
                                              argv[0],
                                              argv[1],
                                              argv[2],
-                                             gnm_range_count,
+                                             range_count,
                                              COLLECT_IGNORE_BLANKS,
                                              GNM_ERROR_UNKNOWN,
-                                             GNM_ERROR_NUM);
+                                             GNM_ERROR_NUM,
+                                             TRUE);
 }
 
 /***************************************************************************/
@@ -462,7 +487,8 @@ gnumeric_dget (GnmFuncEvalInfo *ei, GnmValue const * const *argv)
                                              range_first,
                                              COLLECT_IGNORE_BLANKS,
                                              GNM_ERROR_VALUE,
-                                             GNM_ERROR_NUM);
+                                             GNM_ERROR_NUM,
+                                             FALSE);
 }
 
 static GnmFuncHelp const help_dmax[] = {
diff --git a/src/value.c b/src/value.c
index 88de916..7cd7c65 100644
--- a/src/value.c
+++ b/src/value.c
@@ -1676,7 +1676,7 @@ find_column_of_field (GnmEvalPos const *ep,
        int   begin_col, end_col, row, n, column;
        int   offset;
 
-       // I'm not certain we shoul demand this, but the code clearly wants
+       // I'm not certain we should demand this, but the code clearly wants
        // it.
        if (!VALUE_IS_CELLRANGE (database))
                return -1;