From 887cc68c36f31c5d8796c377919c186870d2b198 Mon Sep 17 00:00:00 2001
From: Matthias Clasen <mclasen@redhat.com>
Date: Sun, 23 May 2021 21:03:22 -0400
Subject: Explicitly preserve unlimited attributes

When calling pango_attr_list_update(), we must not
change the limits or attributes that are unlimited.
---
 pango/pango-attributes.c | 42 ++++++++++++++++++++++++------------------
 1 file changed, 24 insertions(+), 18 deletions(-)

diff --git a/pango/pango-attributes.c b/pango/pango-attributes.c
index 8b4b2f7a..0d604f3d 100644
--- a/pango/pango-attributes.c
+++ b/pango/pango-attributes.c
@@ -1760,28 +1760,34 @@ pango_attr_list_update (PangoAttrList *list,
             continue;
           }
 
-        if (attr->start_index >= pos &&
-            attr->start_index < pos + remove)
-          {
-            attr->start_index = pos + add;
-          }
-        else if (attr->start_index >= pos + remove)
+        if (attr->start_index != PANGO_ATTR_INDEX_FROM_TEXT_BEGINNING)
           {
-            attr->start_index += add - remove;
+            if (attr->start_index >= pos &&
+                attr->start_index < pos + remove)
+              {
+                attr->start_index = pos + add;
+              }
+            else if (attr->start_index >= pos + remove)
+              {
+                attr->start_index += add - remove;
+              }
           }
 
-        if (attr->end_index >= pos &&
-            attr->end_index < pos + remove)
-          {
-            attr->end_index = pos;
-          }
-        else if (attr->end_index >= pos + remove)
+        if (attr->end_index != PANGO_ATTR_INDEX_TO_TEXT_END)
           {
-            if (add > remove &&
-                G_MAXUINT - attr->end_index < add - remove)
-              attr->end_index = G_MAXUINT;
-            else
-              attr->end_index += add - remove;
+            if (attr->end_index >= pos &&
+                attr->end_index < pos + remove)
+              {
+                attr->end_index = pos;
+              }
+            else if (attr->end_index >= pos + remove)
+              {
+                if (add > remove &&
+                    G_MAXUINT - attr->end_index < add - remove)
+                  attr->end_index = G_MAXUINT;
+                else
+                  attr->end_index += add - remove;
+              }
           }
       }
 }
-- 
cgit v1.2.1


From 6e363555a5ed76756a5bc8eb4914dc2e4af9c3b5 Mon Sep 17 00:00:00 2001
From: Matthias Clasen <mclasen@redhat.com>
Date: Sun, 23 May 2021 21:04:11 -0400
Subject:  Add a test for unlimited attributes

Test the fix in the previous commit.
---
 tests/testmisc.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/tests/testmisc.c b/tests/testmisc.c
index 0767eb7a..b4467a63 100644
--- a/tests/testmisc.c
+++ b/tests/testmisc.c
@@ -125,23 +125,33 @@ static void
 test_attr_list_update (void)
 {
   PangoAttribute *weight_attr;
+  PangoAttribute *fg_attr;
   PangoAttrList *list;
 
   weight_attr = pango_attr_weight_new (700);
   weight_attr->start_index = 4;
   weight_attr->end_index = 6;
 
+  fg_attr = pango_attr_foreground_new (0, 0, 65535);
+  fg_attr->start_index = PANGO_ATTR_INDEX_FROM_TEXT_BEGINNING;
+  fg_attr->end_index = PANGO_ATTR_INDEX_TO_TEXT_END;
+
   list = pango_attr_list_new();
   pango_attr_list_insert (list, weight_attr);
+  pango_attr_list_insert (list, fg_attr);
 
   g_assert_cmpuint (weight_attr->start_index, ==, 4);
   g_assert_cmpuint (weight_attr->end_index, ==, 6);
+  g_assert_cmpuint (fg_attr->start_index, ==, PANGO_ATTR_INDEX_FROM_TEXT_BEGINNING);
+  g_assert_cmpuint (fg_attr->end_index, ==, PANGO_ATTR_INDEX_TO_TEXT_END);
 
   // Delete 1 byte at position 2
   pango_attr_list_update (list, 2, 1, 0);
 
   g_assert_cmpuint (weight_attr->start_index, ==, 3);
   g_assert_cmpuint (weight_attr->end_index, ==, 5);
+  g_assert_cmpuint (fg_attr->start_index, ==, PANGO_ATTR_INDEX_FROM_TEXT_BEGINNING);
+  g_assert_cmpuint (fg_attr->end_index, ==, PANGO_ATTR_INDEX_TO_TEXT_END);
 
   pango_attr_list_unref (list);
 }
-- 
cgit v1.2.1