Tweak issue/patch validation rules

Patches - title: mandatory, body: optional.
Issues - title and body: mandatory.

src/components/ExtendedTextarea.svelte

@@ -25,7 +25,10 @@
   export let body: string = "";
   export let embeds: Map<string, Embed> = new Map();
   export let submitInProgress: boolean = false;
-  export let validateBody: boolean = true;
+  export let disallowEmptyBody: boolean = false;
+  export let isValid: () => boolean = () => {
+    return true;
+  };
 
   let preview: boolean = false;
   let selectionStart = 0;
@@ -178,7 +181,7 @@
     </Button>
     <Button
       styleBorderRadius="0"
-      disabled={validateBody && !body}
+      disabled={!isValid()}
       variant={preview ? "selected" : "not-selected"}
       on:click={() => {
         preview = true;
@@ -235,7 +238,9 @@
       </Button>
       <Button
         variant="secondary"
-        disabled={(validateBody && !body) || submitInProgress}
+        disabled={!isValid() ||
+          submitInProgress ||
+          (disallowEmptyBody && body.length === 0)}
         on:click={submit}>
         {#if submitInProgress}
           <Loading small noDelay />

src/views/projects/Issue.svelte

@@ -542,6 +542,8 @@
         <div slot="description">
           {#if issueState !== "read"}
             <ExtendedTextarea
+              isValid={() => newTitle.length > 0}
+              disallowEmptyBody
               rawPath={rawPath(project.head)}
               enableAttachments
               embeds={parseEmbedIntoMap(issue.discussion[0].embeds)}

src/views/projects/Issue/New.svelte

@@ -99,6 +99,8 @@
           <svelte:fragment slot="description">
             <ExtendedTextarea
               rawPath={rawPath(project.head)}
+              disallowEmptyBody
+              isValid={() => issueTitle.length > 0}
               enableAttachments
               submitCaption="Submit"
               placeholder="Write a description"

src/views/projects/Patch.svelte

@@ -766,7 +766,7 @@
           <div class="revision-description">
             {#if session && patchState !== "read" && latestEdit}
               <ExtendedTextarea
-                validateBody={false}
+                isValid={() => patch.title.length > 0}
                 enableAttachments
                 embeds={parseEmbedIntoMap(latestEdit.embeds)}
                 rawPath={rawPath(patch.revisions[0].id)}