Bug 1895922 - Fix locale detection in the crash reporter r=cmartin

Differential Revision: https://phabricator.services.mozilla.com/D209937

toolkit/crashreporter/client/app/src/lang/omnijar.rs

@@ -21,18 +21,57 @@ pub fn read() -> anyhow::Result<LanguageInfo> {
     path.push("omni.ja");
 
     let mut zip = read_omnijar_file(&path)?;
-    let locale = {
+    let locales = {
         let buf = BufReader::new(
             zip.by_name("res/multilocale.txt")
                 .context("failed to read multilocale file in zip archive")?,
         );
-        buf.lines()
+        let line = buf
+            .lines()
             .next()
             .ok_or(anyhow::anyhow!("multilocale file was empty"))?
-            .context("failed to read first line of multilocale file")?
+            .context("failed to read first line of multilocale file")?;
+        line.split(",")
+            .map(|s| s.trim().to_owned())
+            .collect::<Vec<_>>()
     };
 
-    let mut file = zip
+    let (locale, ftl_definitions) = 'defs: {
+        for locale in &locales {
+            match read_strings(locale, &mut zip) {
+                Ok(v) => break 'defs (locale.to_string(), v),
+                Err(e) => log::warn!("{e:#}"),
+            }
+        }
+        anyhow::bail!("failed to find any usable localized strings in the omnijar")
+    };
+
+    // The brand ftl is in the browser omnijar.
+    path.pop();
+    path.push("browser");
+    path.push("omni.ja");
+
+    let ftl_branding = 'branding: {
+        for locale in &locales {
+            match read_branding(&locale, &mut zip) {
+                Ok(v) => break 'branding v,
+                Err(e) => log::warn!("failed to read branding from omnijar: {e:#}"),
+            }
+        }
+        log::info!("using fallback branding info");
+        LanguageInfo::default().ftl_branding
+    };
+
+    Ok(LanguageInfo {
+        identifier: locale,
+        ftl_definitions,
+        ftl_branding,
+    })
+}
+
+/// Read the localized strings from the given zip archive (omnijar).
+fn read_strings(locale: &str, archive: &mut ZipArchive<File>) -> anyhow::Result<String> {
+    let mut file = archive
         .by_name(&format!(
             "localization/{locale}/crashreporter/crashreporter.ftl"
         ))
@@ -42,34 +81,18 @@ pub fn read() -> anyhow::Result<LanguageInfo> {
     file.read_to_string(&mut ftl_definitions)
         .with_context(|| format!("failed to read localization file for {locale}"))?;
 
-    // The brand ftl is in the browser omnijar.
+    Ok(ftl_definitions)
-    path.pop();
+}
-    path.push("browser");
-    path.push("omni.ja");
 
-    let ftl_branding = read_omnijar_file(&path)
+/// Read the branding information from the given zip archive (omnijar).
-        .and_then(|mut zip| {
+fn read_branding(locale: &str, archive: &mut ZipArchive<File>) -> anyhow::Result<String> {
-            let mut file = zip
+    let mut file = archive
-                .by_name(&format!("localization/{locale}/branding/brand.ftl"))
+        .by_name(&format!("localization/{locale}/branding/brand.ftl"))
-                .with_context(|| {
+        .with_context(|| format!("failed to locate branding localization file for {locale}"))?;
-                    format!("failed to locate branding localization file for {locale}")
+    let mut s = String::new();
-                })?;
+    file.read_to_string(&mut s)
-            let mut s = String::new();
+        .with_context(|| format!("failed to read branding localization file for {locale}"))?;
-            file.read_to_string(&mut s)
+    Ok(s)
-                .with_context(|| format!("failed to read localization file for {locale}"))?;
-            Ok(s)
-        })
-        .unwrap_or_else(|e| {
-            log::warn!("failed to read browser omnijar: {e}");
-            log::info!("using fallback branding info");
-            LanguageInfo::default().ftl_branding
-        });
-
-    Ok(LanguageInfo {
-        identifier: locale,
-        ftl_definitions,
-        ftl_branding,
-    })
 }
 
 fn read_omnijar_file(path: &Path) -> anyhow::Result<ZipArchive<File>> {