Switch to libBigWig 0.1.3, which fixes fixed-step files

Author: dpryan79

libBigWig/bigWig.h

@@ -41,7 +41,7 @@
 /*!
  * The library version number
  */
-#define LIBBIGWIG_VERSION 0.1.2
+#define LIBBIGWIG_VERSION 0.1.3
 
 /*!
  * The magic number of a bigWig file.

libBigWig/bwWrite.c

@@ -509,7 +509,7 @@ int bwAddIntervalSpanSteps(bigWigFile_t *fp, char *chrom, uint32_t start, uint32
 
     for(i=0; i<n; i++) {
         if(wb->l + 4 >= fp->hdr->bufSize) {
-            wb->end = wb->start + (wb->l>>2) + step;
+            wb->end = wb->start + ((wb->l-24)>>2) * step;
             flushBuffer(fp);
             wb->start = wb->end;
         }
@@ -532,7 +532,7 @@ int bwAppendIntervalSpanSteps(bigWigFile_t *fp, float *values, uint32_t n) {
 
     for(i=0; i<n; i++) {
         if(wb->l + 4 >= fp->hdr->bufSize) {
-            wb->end = wb->start + (wb->l>>2) + wb->step;
+            wb->end = wb->start + ((wb->l-24)>>2) * wb->step;
             flushBuffer(fp);
             wb->start = wb->end;
         }

setup.py

@@ -34,12 +34,12 @@
                     include_dirs = ['libBigWig', sysconfig.get_config_var("INCLUDEPY")])
 
 setup(name = 'pyBigWig',
-       version = '0.2.2',
+       version = '0.2.3',
        description = 'A package for accessing bigWig files using libBigWig',
        author = "Devon P. Ryan",
        author_email = "[email protected]",
        url = "https://github.com/dpryan79/pyBigWig",
-       download_url = "https://github.com/dpryan79/pyBigWig/tarball/0.2.2",
+       download_url = "https://github.com/dpryan79/pyBigWig/tarball/0.2.3",
        keywords = ["bioinformatics", "bigWig"],
        packages = find_packages(),
        include_package_data=True,