Fixed some issues found by coverity scan

graphviz-2.40.1-coverity-scan-fixes.patch

@@ -0,0 +1,26 @@
+diff --git a/cmd/lefty/dot2l/dotlex.c b/cmd/lefty/dot2l/dotlex.c
+index cf738c0..65e17e2 100644
+--- a/cmd/lefty/dot2l/dotlex.c
++++ b/cmd/lefty/dot2l/dotlex.c
+@@ -252,7 +252,7 @@ static char *scan_token (char *p) {
+     char *q;
+ 
+     q = lexbuf;
+-    if (p == '\0')
++    if (!p || *p == '\0')
+         return NULL;
+     while (isalnum (*p) || (*p == '_') || (!isascii (*p)))
+         *q++ = *p++;
+diff --git a/cmd/tools/gvgen.c b/cmd/tools/gvgen.c
+index 662343e..2925d19 100644
+--- a/cmd/tools/gvgen.c
++++ b/cmd/tools/gvgen.c
+@@ -458,6 +458,8 @@ closeOpen (void)
+ 	fprintf(opts.outfile, "}\ngraph {\n");
+ }
+ 
++extern void makeTetrix(int depth, edgefn ef);
++
+ int main(int argc, char *argv[])
+ {
+     GraphType graphType;

graphviz.spec

@@ -61,7 +61,7 @@
 Name:			graphviz
 Summary:		Graph Visualization Tools
 Version:		2.40.1
-Release:		40%{?dist}
+Release:		41%{?dist}
 License:		EPL-1.0
 URL:			http://www.graphviz.org/
 # A bit hacking needed due to: https://gitlab.com/graphviz/graphviz/issues/1371
@@ -72,6 +72,7 @@ Patch1:			graphviz-2.40.1-python3.patch
 Patch2:			graphviz-2.40.1-CVE-2018-10196.patch
 # rhbz#1505230
 Patch3:			graphviz-2.40.1-dotty-menu-fix.patch
+Patch4:			graphviz-2.40.1-coverity-scan-fixes.patch
 BuildRequires:		zlib-devel, libpng-devel, libjpeg-devel, expat-devel, freetype-devel >= 2
 BuildRequires:		ksh, bison, m4, flex, tk-devel, tcl-devel >= 8.3, swig, sed
 BuildRequires:		fontconfig-devel, libtool-ltdl-devel, ruby-devel, ruby, guile-devel
@@ -287,6 +288,7 @@ Various tcl packages (extensions) for the graphviz tools.
 %patch1 -p1 -b .python3
 %patch2 -p1 -b .CVE-2018-10196
 %patch3 -p1 -b .dotty-menu-fix
+%patch4 -p1 -b .coverity-scan-fixes
 
 # Attempt to fix rpmlint warnings about executable sources
 find -type f -regex '.*\.\(c\|h\)$' -exec chmod a-x {} ';'
@@ -606,6 +608,9 @@ php --no-php-ini \
 %{_mandir}/man3/*.3tcl*
 
 %changelog
+* Fri Dec  7 2018 Jaroslav Škarvada <jskarvad@redhat.com> - 2.40.1-41
+- Fixed some issues found by coverity scan
+
 * Thu Oct 18 2018 Jaroslav Škarvada <jskarvad@redhat.com> - 2.40.1-40
 - Clarified license tag