Fix a crash in tab handlingtab-crash-fix

When we uninsert the current tab run, we need to reset
our tab state to prevent last_tab->glyphs to become a
dangling pointer.

Test included.

Fixes: #634

3 files changed, 1449 insertions, 3 deletions

diff --git a/pango/pango-layout.c b/pango/pango-layout.c
index 060420a8..ed46d57a 100644
--- a/pango/pango-layout.c
+++ b/pango/pango-layout.c
@@ -3775,6 +3775,7 @@ insert_run (PangoLayoutLine  *line,
   if (state->last_tab.glyphs && run->glyphs != state->last_tab.glyphs)
     {
       gboolean found_decimal = FALSE;
+      int width;
 
       /* Adjust the tab position so placing further runs will continue to
        * maintain the tab placement. In the case of decimal tabs, we are
@@ -3794,9 +3795,10 @@ insert_run (PangoLayoutLine  *line,
           state->last_tab.width += width;
         }
 
-      state->last_tab.glyphs->glyphs[0].geometry.width = MAX (state->last_tab.pos - state->last_tab.width, 0);
+      width = MAX (state->last_tab.pos - state->last_tab.width, 0);
+      state->last_tab.glyphs->glyphs[0].geometry.width = width;
 
-      if (found_decimal)
+      if (found_decimal || width == 0)
         state->last_tab.glyphs = NULL;
     }
 }
@@ -4494,7 +4496,21 @@ process_line (PangoLayout    *layout,
         case BREAK_NONE_FIT:
           /* Back up over unused runs to run where there is a break */
           while (line->runs && line->runs != break_link)
-            state->items = g_list_prepend (state->items, uninsert_run (line));
+            {
+              PangoLayoutRun *run = line->runs->data;
+
+              /* If we uninsert the current tab run,
+               * we need to reset the tab state
+               */
+              if (run->glyphs == state->last_tab.glyphs)
+                {
+                  state->last_tab.glyphs = NULL;
+                  state->last_tab.index = 0;
+                  state->last_tab.align = PANGO_TAB_LEFT;
+                }
+
+              state->items = g_list_prepend (state->items, uninsert_run (line));
+            }
 
           state->start_offset = break_start_offset;
           state->remaining_width = break_remaining_width;
diff --git a/tests/layouts/tab-crash.layout b/tests/layouts/tab-crash.layout
new file mode 100644
index 00000000..a0e83f5d
--- /dev/null
+++ b/tests/layouts/tab-crash.layout
@@ -0,0 +1,1429 @@
+{
+  "context" : {
+    "font" : "Monospace 12",
+    "language" : "en-us",
+    "base-gravity" : "south",
+    "gravity-hint" : "natural",
+    "base-dir" : "ltr",
+    "round-glyph-positions" : true,
+    "transform" : [
+      1,
+      0,
+      0,
+      1,
+      0,
+      0
+    ]
+  },
+  "comment" : "Reproducer for #634, crash when the tab run gets uninserted",
+  "text" : "id=3 UNION ALL SELECT NULL, NULL, CONCAT(0x7373737373, 0x73323173656374657374), NULL--\t\t\t\t-->(MYSQL)",
+  "attributes" : [
+    {
+      "end" : 101,
+      "type" : "font-desc",
+      "value" : "Monospace 12"
+    }
+  ],
+  "tabs" : {
+    "positions-in-pixels" : true,
+    "positions" : [
+      {
+        "position" : 80,
+        "alignment" : "left",
+        "decimal-point" : 0
+      }
+    ]
+  },
+  "width" : 587776,
+  "output" : {
+    "is-wrapped" : true,
+    "is-ellipsized" : false,
+    "unknown-glyphs" : 0,
+    "width" : 585728,
+    "height" : 585728,
+    "log-attrs" : [
+      {
+        "char-break" : true,
+        "cursor-position" : true,
+        "word-start" : true,
+        "sentence-boundary" : true,
+        "sentence-start" : true,
+        "backspace-deletes-character" : true,
+        "word-boundary" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true,
+        "break-inserts-hyphen" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true,
+        "word-end" : true,
+        "word-boundary" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true,
+        "word-start" : true,
+        "word-boundary" : true
+      },
+      {
+        "char-break" : true,
+        "white" : true,
+        "cursor-position" : true,
+        "word-end" : true,
+        "expandable-space" : true,
+        "word-boundary" : true
+      },
+      {
+        "line-break" : true,
+        "char-break" : true,
+        "cursor-position" : true,
+        "word-start" : true,
+        "word-boundary" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true,
+        "break-inserts-hyphen" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true,
+        "break-inserts-hyphen" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true,
+        "break-inserts-hyphen" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true,
+        "break-inserts-hyphen" : true
+      },
+      {
+        "char-break" : true,
+        "white" : true,
+        "cursor-position" : true,
+        "word-end" : true,
+        "expandable-space" : true,
+        "word-boundary" : true
+      },
+      {
+        "line-break" : true,
+        "char-break" : true,
+        "cursor-position" : true,
+        "word-start" : true,
+        "word-boundary" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true,
+        "break-inserts-hyphen" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true,
+        "break-inserts-hyphen" : true
+      },
+      {
+        "char-break" : true,
+        "white" : true,
+        "cursor-position" : true,
+        "word-end" : true,
+        "expandable-space" : true,
+        "word-boundary" : true
+      },
+      {
+        "line-break" : true,
+        "char-break" : true,
+        "cursor-position" : true,
+        "word-start" : true,
+        "word-boundary" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true,
+        "break-inserts-hyphen" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true,
+        "break-inserts-hyphen" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true,
+        "break-inserts-hyphen" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true,
+        "break-inserts-hyphen" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true,
+        "break-inserts-hyphen" : true
+      },
+      {
+        "char-break" : true,
+        "white" : true,
+        "cursor-position" : true,
+        "word-end" : true,
+        "expandable-space" : true,
+        "word-boundary" : true
+      },
+      {
+        "line-break" : true,
+        "char-break" : true,
+        "cursor-position" : true,
+        "word-start" : true,
+        "word-boundary" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true,
+        "break-inserts-hyphen" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true,
+        "break-inserts-hyphen" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true,
+        "break-inserts-hyphen" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true,
+        "word-end" : true,
+        "word-boundary" : true
+      },
+      {
+        "char-break" : true,
+        "white" : true,
+        "cursor-position" : true,
+        "expandable-space" : true,
+        "word-boundary" : true
+      },
+      {
+        "line-break" : true,
+        "char-break" : true,
+        "cursor-position" : true,
+        "word-start" : true,
+        "word-boundary" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true,
+        "break-inserts-hyphen" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true,
+        "break-inserts-hyphen" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true,
+        "break-inserts-hyphen" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true,
+        "word-end" : true,
+        "word-boundary" : true
+      },
+      {
+        "char-break" : true,
+        "white" : true,
+        "cursor-position" : true,
+        "expandable-space" : true,
+        "word-boundary" : true
+      },
+      {
+        "line-break" : true,
+        "char-break" : true,
+        "cursor-position" : true,
+        "word-start" : true,
+        "word-boundary" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true,
+        "break-inserts-hyphen" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true,
+        "break-inserts-hyphen" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true,
+        "break-inserts-hyphen" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true,
+        "break-inserts-hyphen" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true,
+        "break-inserts-hyphen" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true,
+        "word-end" : true,
+        "word-boundary" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true,
+        "word-start" : true,
+        "word-boundary" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true,
+        "break-inserts-hyphen" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true,
+        "word-end" : true,
+        "word-boundary" : true
+      },
+      {
+        "char-break" : true,
+        "white" : true,
+        "cursor-position" : true,
+        "expandable-space" : true,
+        "word-boundary" : true
+      },
+      {
+        "line-break" : true,
+        "char-break" : true,
+        "cursor-position" : true,
+        "word-start" : true,
+        "word-boundary" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true,
+        "break-inserts-hyphen" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true,
+        "word-end" : true,
+        "word-boundary" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true,
+        "word-boundary" : true
+      },
+      {
+        "char-break" : true,
+        "white" : true,
+        "cursor-position" : true,
+        "expandable-space" : true,
+        "word-boundary" : true
+      },
+      {
+        "line-break" : true,
+        "char-break" : true,
+        "cursor-position" : true,
+        "word-start" : true,
+        "word-boundary" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true,
+        "break-inserts-hyphen" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true,
+        "break-inserts-hyphen" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true,
+        "break-inserts-hyphen" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true,
+        "word-end" : true,
+        "word-boundary" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true,
+        "word-boundary" : true
+      },
+      {
+        "char-break" : true,
+        "white" : true,
+        "cursor-position" : true,
+        "word-boundary" : true
+      },
+      {
+        "char-break" : true,
+        "white" : true,
+        "cursor-position" : true,
+        "backspace-deletes-character" : true,
+        "word-boundary" : true
+      },
+      {
+        "char-break" : true,
+        "white" : true,
+        "cursor-position" : true,
+        "backspace-deletes-character" : true,
+        "word-boundary" : true
+      },
+      {
+        "char-break" : true,
+        "white" : true,
+        "cursor-position" : true,
+        "backspace-deletes-character" : true,
+        "word-boundary" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true,
+        "backspace-deletes-character" : true,
+        "word-boundary" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true,
+        "word-boundary" : true
+      },
+      {
+        "line-break" : true,
+        "char-break" : true,
+        "cursor-position" : true,
+        "word-boundary" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true,
+        "word-boundary" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true,
+        "word-start" : true,
+        "word-boundary" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true,
+        "break-inserts-hyphen" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true,
+        "break-inserts-hyphen" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true,
+        "break-inserts-hyphen" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true,
+        "break-inserts-hyphen" : true
+      },
+      {
+        "char-break" : true,
+        "cursor-position" : true,
+        "word-end" : true,
+        "word-boundary" : true
+      },
+      {
+        "line-break" : true,
+        "mandatory-break" : true,
+        "char-break" : true,
+        "white" : true,
+        "cursor-position" : true,
+        "sentence-boundary" : true,
+        "sentence-end" : true,
+        "word-boundary" : true
+      }
+    ],
+    "lines" : [
+      {
+        "start-index" : 0,
+        "length" : 55,
+        "paragraph-start" : true,
+        "direction" : "ltr",
+        "runs" : [
+          {
+            "offset" : 0,
+            "length" : 55,
+            "text" : "id=3 UNION ALL SELECT NULL, NULL, CONCAT(0x7373737373, ",
+            "bidi-level" : 0,
+            "gravity" : "south",
+            "language" : "en-us",
+            "script" : "latin",
+            "font" : {
+              "description" : "DejaVu Sans 12",
+              "checksum" : "69ccd07023a72ceb27a5e5c22f728627353b60a198170f5e58dd7014221abf01",
+              "matrix" : [
+                1,
+                -0,
+                -0,
+                1,
+                0,
+                0
+              ]
+            },
+            "flags" : 0,
+            "y-offset" : 0,
+            "start-x-offset" : 0,
+            "end-x-offset" : 0,
+            "glyphs" : [
+              {
+                "glyph" : 76,
+                "width" : 4096,
+                "is-cluster-start" : true,
+                "log-cluster" : 0
+              },
+              {
+                "glyph" : 71,
+                "width" : 10240,
+                "is-cluster-start" : true,
+                "log-cluster" : 1
+              },
+              {
+                "glyph" : 32,
+                "width" : 13312,
+                "is-cluster-start" : true,
+                "log-cluster" : 2
+              },
+              {
+                "glyph" : 22,
+                "width" : 10240,
+                "is-cluster-start" : true,
+                "log-cluster" : 3
+              },
+              {
+                "glyph" : 3,
+                "width" : 5120,
+                "is-cluster-start" : true,
+                "log-cluster" : 4
+              },
+              {
+                "glyph" : 56,
+                "width" : 12288,
+                "is-cluster-start" : true,
+                "log-cluster" : 5
+              },
+              {
+                "glyph" : 49,
+                "width" : 12288,
+                "is-cluster-start" : true,
+                "log-cluster" : 6
+              },
+              {
+                "glyph" : 44,
+                "width" : 5120,
+                "is-cluster-start" : true,
+                "log-cluster" : 7
+              },
+              {
+                "glyph" : 50,
+                "width" : 13312,
+                "is-cluster-start" : true,
+                "log-cluster" : 8
+              },
+              {
+                "glyph" : 49,
+                "width" : 12288,
+                "is-cluster-start" : true,
+                "log-cluster" : 9
+              },
+              {
+                "glyph" : 3,
+                "width" : 5120,
+                "is-cluster-start" : true,
+                "log-cluster" : 10
+              },
+              {
+                "glyph" : 36,
+                "width" : 11264,
+                "is-cluster-start" : true,
+                "log-cluster" : 11
+              },
+              {
+                "glyph" : 47,
+                "width" : 9216,
+                "is-cluster-start" : true,
+                "log-cluster" : 12
+              },
+              {
+                "glyph" : 47,
+                "width" : 9216,
+                "is-cluster-start" : true,
+                "log-cluster" : 13
+              },
+              {
+                "glyph" : 3,
+                "width" : 5120,
+                "is-cluster-start" : true,
+                "log-cluster" : 14
+              },
+              {
+                "glyph" : 54,
+                "width" : 10240,
+                "is-cluster-start" : true,
+                "log-cluster" : 15
+              },
+              {
+                "glyph" : 40,
+                "width" : 10240,
+                "is-cluster-start" : true,
+                "log-cluster" : 16
+              },
+              {
+                "glyph" : 47,
+                "width" : 9216,
+                "is-cluster-start" : true,
+                "log-cluster" : 17
+              },
+              {
+                "glyph" : 40,
+                "width" : 10240,
+                "is-cluster-start" : true,
+                "log-cluster" : 18
+              },
+              {
+                "glyph" : 38,
+                "width" : 11264,
+                "is-cluster-start" : true,
+                "log-cluster" : 19
+              },
+              {
+                "glyph" : 55,
+                "width" : 10240,
+                "is-cluster-start" : true,
+                "log-cluster" : 20
+              },
+              {
+                "glyph" : 3,
+                "width" : 5120,
+                "is-cluster-start" : true,
+                "log-cluster" : 21
+              },
+              {
+                "glyph" : 49,
+                "width" : 12288,
+                "is-cluster-start" : true,
+                "log-cluster" : 22
+              },
+              {
+                "glyph" : 56,
+                "width" : 12288,
+                "is-cluster-start" : true,
+                "log-cluster" : 23
+              },
+              {
+                "glyph" : 47,
+                "width" : 9216,
+                "is-cluster-start" : true,
+                "log-cluster" : 24
+              },
+              {
+                "glyph" : 47,
+                "width" : 9216,
+                "is-cluster-start" : true,
+                "log-cluster" : 25
+              },
+              {
+                "glyph" : 15,
+                "width" : 5120,
+                "is-cluster-start" : true,
+                "log-cluster" : 26
+              },
+              {
+                "glyph" : 3,
+                "width" : 5120,
+                "is-cluster-start" : true,
+                "log-cluster" : 27
+              },
+              {
+                "glyph" : 49,
+                "width" : 12288,
+                "is-cluster-start" : true,
+                "log-cluster" : 28
+              },
+              {
+                "glyph" : 56,
+                "width" : 12288,
+                "is-cluster-start" : true,
+                "log-cluster" : 29
+              },
+              {
+                "glyph" : 47,
+                "width" : 9216,
+                "is-cluster-start" : true,
+                "log-cluster" : 30
+              },
+              {
+                "glyph" : 47,
+                "width" : 9216,
+                "is-cluster-start" : true,
+                "log-cluster" : 31
+              },
+              {
+                "glyph" : 15,
+                "width" : 5120,
+                "is-cluster-start" : true,
+                "log-cluster" : 32
+              },
+              {
+                "glyph" : 3,
+                "width" : 5120,
+                "is-cluster-start" : true,
+                "log-cluster" : 33
+              },
+              {
+                "glyph" : 38,
+                "width" : 11264,
+                "is-cluster-start" : true,
+                "log-cluster" : 34
+              },
+              {
+                "glyph" : 50,
+                "width" : 13312,
+                "is-cluster-start" : true,
+                "log-cluster" : 35
+              },
+              {
+                "glyph" : 49,
+                "width" : 12288,
+                "is-cluster-start" : true,
+                "log-cluster" : 36
+              },
+              {
+                "glyph" : 38,
+                "width" : 11264,
+                "is-cluster-start" : true,
+                "log-cluster" : 37
+              },
+              {
+                "glyph" : 36,
+                "width" : 10240,
+                "is-cluster-start" : true,
+                "log-cluster" : 38
+              },
+              {
+                "glyph" : 55,
+                "width" : 10240,
+                "is-cluster-start" : true,
+                "log-cluster" : 39
+              },
+              {
+                "glyph" : 11,
+                "width" : 6144,
+                "is-cluster-start" : true,
+                "log-cluster" : 40
+              },
+              {
+                "glyph" : 19,
+                "width" : 10240,
+                "is-cluster-start" : true,
+                "log-cluster" : 41
+              },
+              {
+                "glyph" : 91,
+                "width" : 9216,
+                "is-cluster-start" : true,
+                "log-cluster" : 42
+              },
+              {
+                "glyph" : 26,
+                "width" : 10240,
+                "is-cluster-start" : true,
+                "log-cluster" : 43
+              },
+              {
+                "glyph" : 22,
+                "width" : 10240,
+                "is-cluster-start" : true,
+                "log-cluster" : 44
+              },
+              {
+                "glyph" : 26,
+                "width" : 10240,
+                "is-cluster-start" : true,
+                "log-cluster" : 45
+              },
+              {
+                "glyph" : 22,
+                "width" : 10240,
+                "is-cluster-start" : true,
+                "log-cluster" : 46
+              },
+              {
+                "glyph" : 26,
+                "width" : 10240,
+                "is-cluster-start" : true,
+                "log-cluster" : 47
+              },
+              {
+                "glyph" : 22,
+                "width" : 10240,
+                "is-cluster-start" : true,
+                "log-cluster" : 48
+              },
+              {
+                "glyph" : 26,
+                "width" : 10240,
+                "is-cluster-start" : true,
+                "log-cluster" : 49
+              },
+              {
+                "glyph" : 22,
+                "width" : 10240,
+                "is-cluster-start" : true,
+                "log-cluster" : 50
+              },
+              {
+                "glyph" : 26,
+                "width" : 10240,
+                "is-cluster-start" : true,
+                "log-cluster" : 51
+              },
+              {
+                "glyph" : 22,
+                "width" : 10240,
+                "is-cluster-start" : true,
+                "log-cluster" : 52
+              },
+              {
+                "glyph" : 15,
+                "width" : 5120,
+                "is-cluster-start" : true,
+                "log-cluster" : 53
+              },
+              {
+                "glyph" : 268435455,
+                "width" : 0,
+                "is-cluster-start" : true,
+                "log-cluster" : 54
+              }
+            ]
+          }
+        ]
+      },
+      {
+        "start-index" : 55,
+        "length" : 37,
+        "paragraph-start" : false,
+        "direction" : "ltr",
+        "runs" : [
+          {
+            "offset" : 55,
+            "length" : 31,
+            "text" : "0x73323173656374657374), NULL--",
+            "bidi-level" : 0,
+            "gravity" : "south",
+            "language" : "en-us",
+            "script" : "latin",
+            "font" : {
+              "description" : "DejaVu Sans 12",
+              "checksum" : "69ccd07023a72ceb27a5e5c22f728627353b60a198170f5e58dd7014221abf01",
+              "matrix" : [
+                1,
+                -0,
+                -0,
+                1,
+                0,
+                0
+              ]
+            },
+            "flags" : 0,
+            "y-offset" : 0,
+            "start-x-offset" : 0,
+            "end-x-offset" : 0,
+            "glyphs" : [
+              {
+                "glyph" : 19,
+                "width" : 10240,
+                "is-cluster-start" : true,
+                "log-cluster" : 0
+              },
+              {
+                "glyph" : 91,
+                "width" : 9216,
+                "is-cluster-start" : true,
+                "log-cluster" : 1
+              },
+              {
+                "glyph" : 26,
+                "width" : 10240,
+                "is-cluster-start" : true,
+                "log-cluster" : 2
+              },
+              {
+                "glyph" : 22,
+                "width" : 10240,
+                "is-cluster-start" : true,
+                "log-cluster" : 3
+              },
+              {
+                "glyph" : 22,
+                "width" : 10240,
+                "is-cluster-start" : true,
+                "log-cluster" : 4
+              },
+              {
+                "glyph" : 21,
+                "width" : 10240,
+                "is-cluster-start" : true,
+                "log-cluster" : 5
+              },
+              {
+                "glyph" : 22,
+                "width" : 10240,
+                "is-cluster-start" : true,
+                "log-cluster" : 6
+              },
+              {
+                "glyph" : 20,
+                "width" : 10240,
+                "is-cluster-start" : true,
+                "log-cluster" : 7
+              },
+              {
+                "glyph" : 26,
+                "width" : 10240,
+                "is-cluster-start" : true,
+                "log-cluster" : 8
+              },
+              {
+                "glyph" : 22,
+                "width" : 10240,
+                "is-cluster-start" : true,
+                "log-cluster" : 9
+              },
+              {
+                "glyph" : 25,
+                "width" : 10240,
+                "is-cluster-start" : true,
+                "log-cluster" : 10
+              },
+              {
+                "glyph" : 24,
+                "width" : 10240,
+                "is-cluster-start" : true,
+                "log-cluster" : 11
+              },
+              {
+                "glyph" : 25,
+                "width" : 10240,
+                "is-cluster-start" : true,
+                "log-cluster" : 12
+              },
+              {
+                "glyph" : 22,
+                "width" : 10240,
+                "is-cluster-start" : true,
+                "log-cluster" : 13
+              },
+              {
+                "glyph" : 26,
+                "width" : 10240,
+                "is-cluster-start" : true,
+                "log-cluster" : 14
+              },
+              {
+                "glyph" : 23,
+                "width" : 10240,
+                "is-cluster-start" : true,
+                "log-cluster" : 15
+              },
+              {
+                "glyph" : 25,
+                "width" : 10240,
+                "is-cluster-start" : true,
+                "log-cluster" : 16
+              },
+              {
+                "glyph" : 24,
+                "width" : 10240,
+                "is-cluster-start" : true,
+                "log-cluster" : 17
+              },
+              {
+                "glyph" : 26,
+                "width" : 10240,
+                "is-cluster-start" : true,
+                "log-cluster" : 18
+              },
+              {
+                "glyph" : 22,
+                "width" : 10240,
+                "is-cluster-start" : true,
+                "log-cluster" : 19
+              },
+              {
+                "glyph" : 26,
+                "width" : 10240,
+                "is-cluster-start" : true,
+                "log-cluster" : 20
+              },
+              {
+                "glyph" : 23,
+                "width" : 10240,
+                "is-cluster-start" : true,
+                "log-cluster" : 21
+              },
+              {
+                "glyph" : 12,
+                "width" : 6144,
+                "is-cluster-start" : true,
+                "log-cluster" : 22
+              },
+              {
+                "glyph" : 15,
+                "width" : 5120,
+                "is-cluster-start" : true,
+                "log-cluster" : 23
+              },
+              {
+                "glyph" : 3,
+                "width" : 5120,
+                "is-cluster-start" : true,
+                "log-cluster" : 24
+              },
+              {
+                "glyph" : 49,
+                "width" : 12288,
+                "is-cluster-start" : true,
+                "log-cluster" : 25
+              },
+              {
+                "glyph" : 56,
+                "width" : 12288,
+                "is-cluster-start" : true,
+                "log-cluster" : 26
+              },
+              {
+                "glyph" : 47,
+                "width" : 9216,
+                "is-cluster-start" : true,
+                "log-cluster" : 27
+              },
+              {
+                "glyph" : 47,
+                "width" : 9216,
+                "is-cluster-start" : true,
+                "log-cluster" : 28
+              },
+              {
+                "glyph" : 16,
+                "width" : 6144,
+                "is-cluster-start" : true,
+                "log-cluster" : 29
+              },
+              {
+                "glyph" : 16,
+                "width" : 6144,
+                "is-cluster-start" : true,
+                "log-cluster" : 30
+              }
+            ]
+          },
+          {
+            "offset" : 86,
+            "length" : 1,
+            "text" : "\t",
+            "bidi-level" : 0,
+            "gravity" : "south",
+            "language" : "en-us",
+            "script" : "latin",
+            "font" : {
+              "description" : "DejaVu Sans 12",
+              "checksum" : "69ccd07023a72ceb27a5e5c22f728627353b60a198170f5e58dd7014221abf01",
+              "matrix" : [
+                1,
+                -0,
+                -0,
+                1,
+                0,
+                0
+              ]
+            },
+            "flags" : 0,
+            "y-offset" : 0,
+            "start-x-offset" : 0,
+            "end-x-offset" : 0,
+            "glyphs" : [
+              {
+                "glyph" : 268435455,
+                "width" : 31744,
+                "is-cluster-start" : true,
+                "log-cluster" : 0
+              }
+            ]
+          },
+          {
+            "offset" : 87,
+            "length" : 1,
+            "text" : "\t",
+            "bidi-level" : 0,
+            "gravity" : "south",
+            "language" : "en-us",
+            "script" : "latin",
+            "font" : {
+              "description" : "DejaVu Sans 12",
+              "checksum" : "69ccd07023a72ceb27a5e5c22f728627353b60a198170f5e58dd7014221abf01",
+              "matrix" : [
+                1,
+                -0,
+                -0,
+                1,
+                0,
+                0
+              ]
+            },
+            "flags" : 0,
+            "y-offset" : 0,
+            "start-x-offset" : 0,
+            "end-x-offset" : 0,
+            "glyphs" : [
+              {
+                "glyph" : 268435455,
+                "width" : 81920,
+                "is-cluster-start" : true,
+                "log-cluster" : 0
+              }
+            ]
+          },
+          {
+            "offset" : 88,
+            "length" : 1,
+            "text" : "\t",
+            "bidi-level" : 0,
+            "gravity" : "south",
+            "language" : "en-us",
+            "script" : "latin",
+            "font" : {
+              "description" : "DejaVu Sans 12",
+              "checksum" : "69ccd07023a72ceb27a5e5c22f728627353b60a198170f5e58dd7014221abf01",
+              "matrix" : [
+                1,
+                -0,
+                -0,
+                1,
+                0,
+                0
+              ]
+            },
+            "flags" : 0,
+            "y-offset" : 0,
+            "start-x-offset" : 0,
+            "end-x-offset" : 0,
+            "glyphs" : [
+              {
+                "glyph" : 268435455,
+                "width" : 81920,
+                "is-cluster-start" : true,
+                "log-cluster" : 0
+              }
+            ]
+          },
+          {
+            "offset" : 89,
+            "length" : 1,
+            "text" : "\t",
+            "bidi-level" : 0,
+            "gravity" : "south",
+            "language" : "en-us",
+            "script" : "latin",
+            "font" : {
+              "description" : "DejaVu Sans 12",
+              "checksum" : "69ccd07023a72ceb27a5e5c22f728627353b60a198170f5e58dd7014221abf01",
+              "matrix" : [
+                1,
+                -0,
+                -0,
+                1,
+                0,
+                0
+              ]
+            },
+            "flags" : 0,
+            "y-offset" : 0,
+            "start-x-offset" : 0,
+            "end-x-offset" : 0,
+            "glyphs" : [
+              {
+                "glyph" : 268435455,
+                "width" : 81920,
+                "is-cluster-start" : true,
+                "log-cluster" : 0
+              }
+            ]
+          },
+          {
+            "offset" : 90,
+            "length" : 2,
+            "text" : "--",
+            "bidi-level" : 0,
+            "gravity" : "south",
+            "language" : "en-us",
+            "script" : "latin",
+            "font" : {
+              "description" : "DejaVu Sans 12",
+              "checksum" : "69ccd07023a72ceb27a5e5c22f728627353b60a198170f5e58dd7014221abf01",
+              "matrix" : [
+                1,
+                -0,
+                -0,
+                1,
+                0,
+                0
+              ]
+            },
+            "flags" : 0,
+            "y-offset" : 0,
+            "start-x-offset" : 0,
+            "end-x-offset" : 0,
+            "glyphs" : [
+              {
+                "glyph" : 16,
+                "width" : 6144,
+                "is-cluster-start" : true,
+                "log-cluster" : 0
+              },
+              {
+                "glyph" : 16,
+                "width" : 6144,
+                "is-cluster-start" : true,
+                "log-cluster" : 1
+              }
+            ]
+          }
+        ]
+      },
+      {
+        "start-index" : 92,
+        "length" : 8,
+        "paragraph-start" : false,
+        "direction" : "ltr",
+        "runs" : [
+          {
+            "offset" : 92,
+            "length" : 8,
+            "text" : ">(MYSQL)",
+            "bidi-level" : 0,
+            "gravity" : "south",
+            "language" : "en-us",
+            "script" : "latin",
+            "font" : {
+              "description" : "DejaVu Sans 12",
+              "checksum" : "69ccd07023a72ceb27a5e5c22f728627353b60a198170f5e58dd7014221abf01",
+              "matrix" : [
+                1,
+                -0,
+                -0,
+                1,
+                0,
+                0
+              ]
+            },
+            "flags" : 0,
+            "y-offset" : 0,
+            "start-x-offset" : 0,
+            "end-x-offset" : 0,
+            "glyphs" : [
+              {
+                "glyph" : 33,
+                "width" : 13312,
+                "is-cluster-start" : true,
+                "log-cluster" : 0
+              },
+              {
+                "glyph" : 11,
+                "width" : 6144,
+                "is-cluster-start" : true,
+                "log-cluster" : 1
+              },
+              {
+                "glyph" : 48,
+                "width" : 14336,
+                "is-cluster-start" : true,
+                "log-cluster" : 2
+              },
+              {
+                "glyph" : 60,
+                "width" : 10240,
+                "is-cluster-start" : true,
+                "log-cluster" : 3
+              },
+              {
+                "glyph" : 54,
+                "width" : 10240,
+                "is-cluster-start" : true,
+                "log-cluster" : 4
+              },
+              {
+                "glyph" : 52,
+                "width" : 13312,
+                "is-cluster-start" : true,
+                "log-cluster" : 5
+              },
+              {
+                "glyph" : 47,
+                "width" : 9216,
+                "is-cluster-start" : true,
+                "log-cluster" : 6
+              },
+              {
+                "glyph" : 12,
+                "width" : 6144,
+                "is-cluster-start" : true,
+                "log-cluster" : 7
+              }
+            ]
+          }
+        ]
+      }
+    ]
+  }
+}
diff --git a/tests/meson.build b/tests/meson.build
index 2658f0a2..2acf0def 100644
--- a/tests/meson.build
+++ b/tests/meson.build
@@ -118,6 +118,7 @@ installed_test_layouts_data = [
   'layouts/valid-20.layout',
   'layouts/valid-21.layout',
   'layouts/valid-22.layout',
+  'layouts/tab-crash.layout',
 ]
 
 test_markups_data = [