[groff] 02/08: [troff]: Fix regression in \O2 escape handling.

[G. Branden Robinson]

gbranden pushed a commit to branch master
in repository groff.

commit 991aa9daf607765fecb92f9476055d057b3d36e2
Author: G. Branden Robinson <g.branden.robinson@gmail.com>
AuthorDate: Fri Jul 30 13:04:24 2021 +1000

    [troff]: Fix regression in \O2 escape handling.
    
    Fix regression (breaking important pdfmark/pdfroff features) caused by
    my commit e876d4bfd193abb9a7d1fb6e76519349bded482a, 27 July.  An empty
    image file name is in fact semantically valid when writing a bounding
    box; pdfmark uses such boxes to frame hyperlinks.  Avoid null pointer
    dereference by initializing `image_filename` to an empty string literal.
    Thanks to Tadziu Hoffman and Keith Marshall for their patient
    explanations.
---
 ChangeLog               | 11 +++++++++++
 src/roff/troff/node.cpp |  2 +-
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/ChangeLog b/ChangeLog
index 113cbb5..e1021f0 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,14 @@
+2021-07-30  G. Branden Robinson <g.branden.robinson@gmail.com>
+
+       [troff]: Fix regression (breaking important pdfmark/pdfroff
+       features) caused by my commit
+       e876d4bfd193abb9a7d1fb6e76519349bded482a, 27 July.  An empty
+       image file name is in fact semantically valid when writing a
+       bounding box; pdfmark uses such boxes to frame hyperlinks.
+       Avoid null pointer dereference by initializing `image_filename`
+       to an empty string literal.  Thanks to Tadziu Hoffman and Keith
+       Marshall for their patient explanations.
+
 2021-07-29  G. Branden Robinson <g.branden.robinson@gmail.com>
 
        [troff]: Refactor some internal functions.
diff --git a/src/roff/troff/node.cpp b/src/roff/troff/node.cpp
index fdb52c7..f20b3ba 100644
--- a/src/roff/troff/node.cpp
+++ b/src/roff/troff/node.cpp
@@ -4052,7 +4052,7 @@ void suppress_node::put(troff_output_file *out, const 
char *s)
  */
 
 static char last_position = 0;
-static const char *image_filename = 0;
+static const char *image_filename = "";
 static int subimage_counter = 0;
 
 inline int min(int a, int b)