[json-glib] Don't loose decimal in whole-double -> string conversion

[Emmanuele Bassi <ebassi src gnome org>]

commit b9007d48d0a3f3d819d727d825fa589fa9cc9557
Author: djcb <djcb djcbsoftware nl>
Date:   Tue Aug 18 16:18:02 2015 +0300

    Don't loose decimal in whole-double -> string conversion
    
    When converting json to its string representation, whole-doubles (such
    as 1.0) would be converted into strings without decimals ("1"). That can
    be inconvenient e.g. when converting from/to GVariants.
    
    To avoid this, append '.0' to the string representation for doubles if
    they lost their decimals in the conversion.
    
    Also add / update unit tests for this.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=753763

 json-glib/json-generator.c  |    5 +++++
 json-glib/tests/generator.c |   22 ++++++++++++++++++++++
 json-glib/tests/gvariant.c  |    4 ++--
 3 files changed, 29 insertions(+), 2 deletions(-)
---
diff --git a/json-glib/json-generator.c b/json-glib/json-generator.c
index 42681f6..879f3be 100644
--- a/json-glib/json-generator.c
+++ b/json-glib/json-generator.c
@@ -342,6 +342,11 @@ dump_value (JsonGenerator *generator,
         g_string_append (buffer,
                          g_ascii_dtostr (buf, sizeof (buf),
                                          json_value_get_double (value)));
+       /* ensure doubles don't become ints */
+       if (g_strstr_len (buf, G_ASCII_DTOSTR_BUF_SIZE, ".") == NULL)
+         {
+           g_string_append (buffer, ".0");
+          }
       }
       break;
 
diff --git a/json-glib/tests/generator.c b/json-glib/tests/generator.c
index 79b6887..e7dabff 100644
--- a/json-glib/tests/generator.c
+++ b/json-glib/tests/generator.c
@@ -335,6 +335,27 @@ test_decimal_separator (void)
   json_node_free (node);
 }
 
+
+static void
+test_double_stays_double (void)
+{
+  gchar *str;
+  JsonNode *node = json_node_new (JSON_NODE_VALUE);
+  JsonGenerator *generator = json_generator_new ();
+
+  json_node_set_double (node, 1.0);
+
+  json_generator_set_root (generator, node);
+
+  str = json_generator_to_data (generator, NULL);
+  g_assert_cmpstr (str, ==, "1.0");
+
+  g_free (str);
+  g_object_unref (generator);
+  json_node_free (node);
+}
+
+
 static void
 test_pretty (void)
 {
@@ -427,6 +448,7 @@ main (int   argc,
   g_test_add_func ("/generator/simple-object", test_simple_object);
   g_test_add_func ("/generator/nested-object", test_nested_object);
   g_test_add_func ("/generator/decimal-separator", test_decimal_separator);
+  g_test_add_func ("/generator/double-stays-double", test_double_stays_double);
   g_test_add_func ("/generator/pretty", test_pretty);
 
   for (i = 0; i < G_N_ELEMENTS (string_fixtures); i++)
diff --git a/json-glib/tests/gvariant.c b/json-glib/tests/gvariant.c
index 701997d..e88b1b9 100644
--- a/json-glib/tests/gvariant.c
+++ b/json-glib/tests/gvariant.c
@@ -45,7 +45,7 @@ static const TestCase two_way_test_cases[] =
     { "/double", "(d)", "(1.23,)", "[1.23]" },
 
     /* double */
-    { "/double-whole", "(d)", "(123.0,)", "[123]" },
+    { "/double-whole", "(d)", "(123.0,)", "[123.0]" },
 
     /* string */
     { "/string", "(s)", "('hello world!',)", "[\"hello world!\"]" },
@@ -158,7 +158,7 @@ static const TestCase json_to_gvariant_test_cases[] =
     { "/string-to-int64", "(x)", "(int64 -666999666999,)", "[\"-666999666999\"]" },
     { "/string-to-uint64", "(t)", "(uint64 1999999999999999,)", "[\"1999999999999999\"]" },
     { "/string-to-double", "(d)", "(1.23,)", "[\"1.23\"]" },
-    { "/string-to-double-whole", "(d)", "(123.0,)", "[\"123\"]" },
+    { "/string-to-double-whole", "(d)", "(123.0,)", "[\"123.0\"]" },
   };
 
 static void