Do not trust isalpha(c) for values > 255.

Fixes #174.

AvailableColumnsPanel.c

@@ -55,7 +55,7 @@ static HandlerResult AvailableColumnsPanel_eventHandler(Panel* super, int ch) {
       }
       default:
       {
-         if (isalpha(ch))
+         if (ch < 255 && isalpha(ch))
             result = Panel_selectByTyping(super, ch);
          break;
       }

CategoriesPanel.c

@@ -102,7 +102,7 @@ static HandlerResult CategoriesPanel_eventHandler(Panel* super, int ch) {
          break;
       }
       default:
-         if (isalpha(ch))
+         if (ch < 255 && isalpha(ch))
             result = Panel_selectByTyping(super, ch);
          if (result == BREAK_LOOP)
             result = IGNORED;

ColumnsPanel.c

@@ -70,7 +70,7 @@ static HandlerResult ColumnsPanel_eventHandler(Panel* super, int ch) {
       }
       default:
       {
-         if (isalpha(ch))
+         if (ch < 255 && isalpha(ch))
             result = Panel_selectByTyping(super, ch);
          if (result == BREAK_LOOP)
             result = IGNORED;

IncSet.c

@@ -153,7 +153,7 @@ bool IncSet_handleKey(IncSet* this, int ch, Panel* panel, IncMode_GetPanelValue
          }
       }
       doSearch = false;
-   } else if (isprint((char)ch) && (mode->index < INCMODE_MAX)) {
+   } else if (ch < 255 && isprint((char)ch) && (mode->index < INCMODE_MAX)) {
       mode->buffer[mode->index] = ch;
       mode->index++;
       mode->buffer[mode->index] = 0;

Panel.c

@@ -427,7 +427,7 @@ HandlerResult Panel_selectByTyping(Panel* this, int ch) {
    if (!this->eventHandlerBuffer)
       this->eventHandlerBuffer = calloc(100, 1);
 
-   if (isalnum(ch)) {
+   if (ch < 255 && isalnum(ch)) {
       int len = strlen(this->eventHandlerBuffer);
       if (len < 99) {
          this->eventHandlerBuffer[len] = ch;

RichString.c

@@ -128,7 +128,7 @@ static inline void RichString_writeFrom(RichString* this, int attrs, const char*
    int newLen = from + len;
    RichString_setLen(this, newLen);
    for (int i = from, j = 0; i < newLen; i++, j++)
-      this->chptr[i] = (isprint(data_c[j]) ? data_c[j] : '?') | attrs;
+      this->chptr[i] = (data_c[j] >= 32 ? data_c[j] : '?') | attrs;
    this->chptr[newLen] = 0;
 }
 

htop.c

@@ -852,7 +852,7 @@ int main(int argc, char** argv) {
          continue;
       }
       
-      if (isdigit((char)ch)) {
+      if (ch < 255 && isdigit((char)ch)) {
          if (Panel_size(panel) == 0) continue;
          pid_t pid = ch-48 + acc;
          for (int i = 0; i < ProcessList_size(pl); i++) {