Handle missing Inspire citation counts

README.md

@@ -26,7 +26,7 @@ Code for this extension is based on the [Zotero DOI
 - Run Zotero (version 5.x)
 - Go to `Tools -> Add-ons`
 - `Install Add-on From File`
-- Choose the file `zotero-citationcounts-0.1.3.xpi`
+- Choose the file `zotero-citationcounts-0.1.4.xpi`
 - Restart Zotero
 
 ## License

chrome/content/scripts/zoterocitationcounts.js

@@ -110,9 +110,14 @@ async function getInspireCount(item, idtype) {
     } else if (idtype == 'arxiv') {
         const arxiv = item.getField('url'); // check URL for arXiv id
         const patt = /(?:arxiv.org[/]abs[/]|arXiv:)([a-z.-]+[/]\d+|\d+[.]\d+)/i;
-        doi = patt.exec(arxiv)[1];
+        const m = patt.exec(arxiv);
+        if (!m) {
+            // No arxiv id found
+            return -1;
+        }
+        doi = m[1];
     } else {
-        // Error
+        // Internal error
         return -1;
     }
     if (!doi) {

install.rdf

@@ -7,7 +7,7 @@
         RDF:about="urn:mozilla:install-manifest"
         em:id="[email protected]"
         em:name="Zotero Citation Counts Manager"
-        em:version="0.1.3"
+        em:version="0.1.4"
         em:type="2"
         em:creator="Erik Schnetter"
         em:description="Automatically fetch and update citation counts"

update.rdf

@@ -5,13 +5,13 @@
       <rdf:Seq>
         <rdf:li>
           <rdf:Description>
-            <em:version>0.1.3</em:version>
+            <em:version>0.1.4</em:version>
             <em:targetApplication>
               <rdf:Description>
                 <em:id>[email protected]</em:id>
                 <em:minVersion>5.0</em:minVersion>
                 <em:maxVersion>5.*</em:maxVersion>
-                <em:updateLink>https://github.com/eschnett/zotero-citationcounts/releases/download/v0.1.3/zotero-citationcounts-0.1.3.xpi</em:updateLink>
+                <em:updateLink>https://github.com/eschnett/zotero-citationcounts/releases/download/v0.1.4/zotero-citationcounts-0.1.4.xpi</em:updateLink>
               </rdf:Description>
             </em:targetApplication>
           </rdf:Description>