[gnumeric] sample_datasource: fix problem with partial lines.

[Morten Welinder <mortenw src gnome org>]

commit 1269feecf9accbb4add5a5d85d6b761e5597a478
Author: Morten Welinder <terra gnome org>
Date:   Thu May 28 19:14:56 2020 -0400

    sample_datasource: fix problem with partial lines.

 NEWS                                          |  1 +
 plugins/sample_datasource/ChangeLog           |  5 +++
 plugins/sample_datasource/sample_datasource.c | 45 ++++++++++++++++++++++-----
 3 files changed, 43 insertions(+), 8 deletions(-)
---
diff --git a/NEWS b/NEWS
index 8e3637337..6cc9acf38 100644
--- a/NEWS
+++ b/NEWS
@@ -12,6 +12,7 @@ Jean:
 
 Morten:
        * Fix performace issue with sample_datasource.  [#491]
+       * Fix partial-line issue with sample_datasource.
 
 --------------------------------------------------------------------------
 Gnumeric 1.12.47
diff --git a/plugins/sample_datasource/ChangeLog b/plugins/sample_datasource/ChangeLog
index 17d975ef6..70cac783d 100644
--- a/plugins/sample_datasource/ChangeLog
+++ b/plugins/sample_datasource/ChangeLog
@@ -1,3 +1,8 @@
+2020-05-28  Morten Welinder  <terra gnome org>
+
+       * sample_datasource.c (cb_atl_input): Buffer a partial line.
+       Recalc at the end, if needed, not for every line.
+
 2020-05-09  Morten Welinder <terra gnome org>
 
        * Release 1.12.47
diff --git a/plugins/sample_datasource/sample_datasource.c b/plugins/sample_datasource/sample_datasource.c
index 54acc6de6..9825ffd97 100644
--- a/plugins/sample_datasource/sample_datasource.c
+++ b/plugins/sample_datasource/sample_datasource.c
@@ -51,6 +51,7 @@ static gboolean debug;
 static int    atl_fd = -1;
 static char * atl_filename = NULL;
 static FILE  *atl_file = NULL;
+static GString *atl_buffer = NULL;
 static guint  atl_source = 0;
 static GHashTable *watched_values = NULL;
 static GHashTable *watchers = NULL;
@@ -107,15 +108,30 @@ cb_watcher_queue_recalc (gpointer key, gpointer value, gpointer closure)
 static gboolean
 cb_atl_input (GIOChannel *gioc, GIOCondition cond, gpointer ignored)
 {
-       char buf[128];
        gboolean any = FALSE;
+       size_t used = 0;
+
+       // quick format ticker:value\n
+       // there is no notion of a field for now.
+       while (TRUE) {
+               char *sym;
+               char *value_str;
+               char *eol;
+               int c;
+
+               while ((c = fgetc (atl_file)) != EOF) {
+                       g_string_append_c (atl_buffer, c);
+                       if (c == '\n')
+                               break;
+               }
+
+               sym = atl_buffer->str + used;
+               eol = strchr (sym, '\n');
+               if (!eol)
+                       break;
+               *eol = 0;
 
-       /* quick format ticker:value\n
-        * there is no notion of a field for now.
-        */
-       while (fgets (buf, sizeof (buf), atl_file) != NULL) {
-               char *sym = buf;
-               char *value_str = strchr (buf, ':');
+               value_str = strchr (sym, ':');
 
                if (value_str != NULL) {
                        gnm_float val;
@@ -123,7 +139,7 @@ cb_atl_input (GIOChannel *gioc, GIOCondition cond, gpointer ignored)
                        *value_str++ = '\0';
 
                        val = gnm_strto (value_str, &end);
-                       if (sym != end && errno == 0) {
+                       if (value_str != end && errno == 0) {
                                WatchedValue *wv = watched_value_fetch (sym);
                                wv->valid = TRUE;
                                wv->value = val;
@@ -135,7 +151,13 @@ cb_atl_input (GIOChannel *gioc, GIOCondition cond, gpointer ignored)
                                        g_printerr ("'%s' <= %" GNM_FORMAT_f "\n", sym, val);
                        }
                }
+               used += eol - sym + 1;
+               if (used == atl_buffer->len) {
+                       g_string_set_size (atl_buffer, 0);
+                       used = 0;
+               }
        }
+       g_string_erase (atl_buffer, 0, used);
        if (any)
                gnm_app_recalc ();
 
@@ -241,6 +263,8 @@ go_plugin_init (GOPlugin *plugin, GOCmdContext *cc)
 #endif /* HAVE_MKFIFO */
                g_free (filename);
 
+       atl_buffer = g_string_new (NULL);
+
        if (atl_fd >= 0) {
                atl_file = fdopen (atl_fd, "rb");
                channel = g_io_channel_unix_new (atl_fd);
@@ -287,6 +311,11 @@ go_plugin_shutdown (GOPlugin *plugin, GOCmdContext *cc)
                atl_file = NULL;
        }
 
+       if (atl_buffer) {
+               g_string_free (atl_buffer, TRUE);
+               atl_buffer = NULL;
+       }
+
        g_hash_table_destroy (watched_values);
        watched_values = NULL;
        g_hash_table_destroy (watchers);