diff --git a/doxygen-empty-strings-segfault.patch b/doxygen-empty-strings-segfault.patch
new file mode 100644
index 0000000..af5a50d
--- /dev/null
+++ b/doxygen-empty-strings-segfault.patch
@@ -0,0 +1,45 @@
+diff --git a/src/util.cpp b/src/util.cpp
+index f9c2492fb..9a0e513b5 100644
+--- a/src/util.cpp
++++ b/src/util.cpp
+@@ -5444,6 +5444,7 @@ QCString escapeCharsInString(const char *name,bool allowDots,bool allowUnderscor
+   static bool allowUnicodeNames = Config_getBool(ALLOW_UNICODE_NAMES);
+   static GrowBuf growBuf;
+   growBuf.clear();
++  if (name==0) return "";
+   char c;
+   const char *p=name;
+   while ((c=*p++)!=0)
+@@ -6962,6 +6963,7 @@ void filterLatexString(FTextStream &t,const char *str,
+ 
+ QCString latexEscapeLabelName(const char *s)
+ {
++  if (s==0) return "";
+   QGString result;
+   QCString tmp(qstrlen(s)+1);
+   FTextStream t(&result);
+@@ -6999,6 +7001,7 @@ QCString latexEscapeLabelName(const char *s)
+ 
+ QCString latexEscapeIndexChars(const char *s)
+ {
++  if (s==0) return "";
+   QGString result;
+   QCString tmp(qstrlen(s)+1);
+   FTextStream t(&result);
+@@ -7037,6 +7040,7 @@ QCString latexEscapeIndexChars(const char *s)
+ 
+ QCString latexEscapePDFString(const char *s)
+ {
++  if (s==0) return "";
+   QGString result;
+   FTextStream t(&result);
+   const char *p=s;
+@@ -7061,6 +7065,7 @@ QCString latexEscapePDFString(const char *s)
+ 
+ QCString latexFilterURL(const char *s)
+ {
++  if (s==0) return "";
+   QGString result;
+   FTextStream t(&result);
+   const char *p=s;
+
diff --git a/doxygen.changes b/doxygen.changes
index ef49c8b..dd78850 100644
--- a/doxygen.changes
+++ b/doxygen.changes
@@ -3,6 +3,8 @@ Mon Jan  7 14:45:46 UTC 2019 - Petr Gajdos <pgajdos@suse.com>
 
 - add doxygen-latex-makeindex.patch to fix build of libssh and
   cmocka [https://github.com/doxygen/doxygen/issues/6725]
+- add doxygen-empty-strings-segfault.patch to fix build of ldb
+  [https://github.com/doxygen/doxygen/pull/6751]
 
 -------------------------------------------------------------------
 Mon Dec 31 08:45:19 UTC 2018 - Petr Gajdos <pgajdos@suse.com>
diff --git a/doxygen.spec b/doxygen.spec
index 0d00cdf..0bc58bb 100644
--- a/doxygen.spec
+++ b/doxygen.spec
@@ -35,6 +35,8 @@ Patch3:         vhdlparser-no-return.patch
 Patch4:         doxygen-dot-one-thread.patch
 # https://github.com/doxygen/doxygen/issues/6725
 Patch5:         doxygen-latex-makeindex.patch
+# https://github.com/doxygen/doxygen/issues/6749
+Patch6:         doxygen-empty-strings-segfault.patch
 BuildRequires:  bison
 BuildRequires:  cmake >= 2.8.12
 BuildRequires:  flex
@@ -62,6 +64,7 @@ as well.
 %patch4 -p1
 %endif
 %patch5 -p1
+%patch6 -p1
 
 %build
 %cmake \