[genius] * compil.c: Fix encoding empty string, affected functions are PrintTable and string

[Jiri (George) Lebl <jirka src gnome org>]

commit 81ee58026d8e7505be8bb64d35481856e2a3f4ad
Author: Jiri (George) Lebl <jiri lebl gmail com>
Date:   Mon Dec 9 09:22:39 2019 -0600

            * compil.c: Fix encoding empty string, affected functions are
              PrintTable and string

 ChangeLog           | 5 +++++
 src/compil.c        | 2 +-
 src/geniustests.txt | 1 +
 3 files changed, 7 insertions(+), 1 deletion(-)
---
diff --git a/ChangeLog b/ChangeLog
index 508c293e..4f6617bf 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Mon Dec 09 09:21:55 2019  Jiri (George) Lebl <jirka 5z com>
+
+       * compil.c: Fix encoding empty string, affected functions are
+         PrintTable and string
+
 Wed Oct 24 20:33:24 2018  Jiri (George) Lebl <jirka 5z com>
 
        * lib/linear_algebra/misc.gel: optimize the Make(Row)Vector functions
diff --git a/src/compil.c b/src/compil.c
index 5044d421..9183f386 100644
--- a/src/compil.c
+++ b/src/compil.c
@@ -77,7 +77,7 @@ char *
 gel_encode_string (const char *s)
 {
        if (ve_string_empty (s)) {
-               return g_strdup ("");
+               return g_strdup ("=");
        } else if (is_ok_ascii (s)) {
                return g_strdup (s);
        } else {
diff --git a/src/geniustests.txt b/src/geniustests.txt
index 06244f58..5bebe09c 100644
--- a/src/geniustests.txt
+++ b/src/geniustests.txt
@@ -1332,6 +1332,7 @@ v=[1,2,3];w=AppendElement(v,v);v                          [1,2,3]
 AppendElement(null,null)                                       [(null)]
 AppendElement([1,2,3],null)                                    [1,2,3,(null)]
 AppendElement(1,1)                                             AppendElement(1,1)
+string(55)                                                     "55"
 load "nullspacetest.gel"                                       true
 load "longtest.gel"                                            true
 load "testprec.gel"                                            true