Motivation

TextInputOutlined and TextInputFlat destructure fontWeight from the user's style prop and spread it after the theme font object:

const { fontWeight } = (StyleSheet.flatten(style) || {}) as TextStyle;
// ...
textStyle: { ...font, fontSize, lineHeight, fontWeight }

When the user doesn't provide fontWeight in their style (the common case — most <TextInput> usage omits it), the destructured value is undefined. Spreading { ...font, fontWeight: undefined } then overrides font.fontWeight (e.g. '400' from the theme) with undefined.

On React Native's Fabric renderer (New Architecture), this undefined flows as nil to the native RCTGetFontWeight function, which passes it to CFStringFind → CFStringGetLength on a NULL pointer → EXC_BAD_ACCESS (SIGSEGV).

This is a fatal crash that kills the app on any screen with a <TextInput> that doesn't explicitly set fontWeight in its style prop. Reproduced on iOS with React Native 0.78 + react-native-paper 5.15.0 + Fabric enabled.

Related issue

No existing issue — discovered via Crashlytics crash report in production. Native crash stack:

Thread 4 Crashed:
0  CoreFoundation    CF_IS_OBJC + 12
1  CoreFoundation    CFStringGetLength + 232
2  CoreFoundation    CFStringFind + 60
3  React             RCTGetFontWeight + 212
4  React             RCTFontWithFontProperties + 3024
5  React             RCTNSTextAttributesFromTextAttributes + 316
6  React             RCTNSAttributedStringFromAttributedString + 364
7  React             -[RCTTextLayoutManager measureAttributedString:...] + 76

Test plan

1. Render <TextInput mode="outlined" /> without a fontWeight in the style prop → previously crashes on Fabric, now uses theme font's fontWeight
2. Render <TextInput mode="outlined" style={{ fontWeight: '700' }} /> → still applies the user-provided weight (nullish coalescing only kicks in for undefined/null)
3. Both TextInputOutlined and TextInputFlat are patched with the same fix
4. Lint, TypeScript, and tests should pass — the change is a single-line nullish coalescing fallback per file