Don't simply trust that string splits were successful...

ProcessList.c

@@ -475,10 +475,14 @@ static void ProcessList_readCGroupFile(Process* process, const char* dirname, co
    char *ok = fgets(buffer, 255, file);
    if (ok) {
       char* trimmed = String_trim(buffer);
-      char** fields = String_split(trimmed, ':');
+      int nFields;
+      char** fields = String_split(trimmed, ':', &nFields);
       free(trimmed);
-
-      process->cgroup = strndup(fields[2] + 1, 10);
+      if (nFields >= 3) {
+         process->cgroup = strndup(fields[2] + 1, 10);
+      } else {
+         process->cgroup = strdup("");
+      }
       String_freeArray(fields);
    }
    fclose(file);

Settings.c

@@ -34,10 +34,10 @@ void Settings_delete(Settings* this) {
 
 static void Settings_readMeters(Settings* this, char* line, HeaderSide side) {
    char* trim = String_trim(line);
-   char** ids = String_split(trim, ' ');
+   int nIds;
+   char** ids = String_split(trim, ' ', &nIds);
    free(trim);
-   int i;
-   for (i = 0; ids[i] != NULL; i++) {
+   for (int i = 0; ids[i]; i++) {
       Header_createMeter(this->header, ids[i], side);
    }
    String_freeArray(ids);
@@ -45,10 +45,10 @@ static void Settings_readMeters(Settings* this, char* line, HeaderSide side) {
 
 static void Settings_readMeterModes(Settings* this, char* line, HeaderSide side) {
    char* trim = String_trim(line);
-   char** ids = String_split(trim, ' ');
+   int nIds;
+   char** ids = String_split(trim, ' ', &nIds);
    free(trim);
-   int i;
-   for (i = 0; ids[i] != NULL; i++) {
+   for (int i = 0; ids[i]; i++) {
       int mode = atoi(ids[i]);
       Header_setMode(this->header, i, mode, side);
    }
@@ -67,13 +67,19 @@ static bool Settings_read(Settings* this, char* fileName) {
    char buffer[maxLine];
    bool readMeters = false;
    while (fgets(buffer, maxLine, fd)) {
-      char** option = String_split(buffer, '=');
+      int nOptions;
+      char** option = String_split(buffer, '=', &nOptions);
+      if (nOptions < 2) {
+         String_freeArray(option);
+         continue;
+      }
       if (String_eq(option[0], "fields")) {
          char* trim = String_trim(option[1]);
-         char** ids = String_split(trim, ' ');
+         int nIds;
+         char** ids = String_split(trim, ' ', &nIds);
          free(trim);
          int i, j;
-         for (j = 0, i = 0; i < LAST_PROCESSFIELD && ids[i] != NULL; i++) {
+         for (j = 0, i = 0; i < LAST_PROCESSFIELD && ids[i]; i++) {
             // This "+1" is for compatibility with the older enum format.
             int id = atoi(ids[i]) + 1;
             if (id > 0 && id < LAST_PROCESSFIELD) {

String.c

@@ -55,7 +55,8 @@ inline int String_eq(const char* s1, const char* s2) {
    return (strcmp(s1, s2) == 0);
 }
 
-char** String_split(const char* s, char sep) {
+char** String_split(const char* s, char sep, int* n) {
+   *n = 0;
    const int rate = 10;
    char** out = (char**) malloc(sizeof(char*) * rate);
    int ctr = 0;
@@ -83,6 +84,7 @@ char** String_split(const char* s, char sep) {
    }
    out = realloc(out, sizeof(char*) * (ctr + 1));
    out[ctr] = NULL;
+   *n = ctr;
    return out;
 }
 

String.h

@@ -27,7 +27,7 @@ char* String_trim(const char* in);
 
 extern int String_eq(const char* s1, const char* s2);
 
-char** String_split(const char* s, char sep);
+char** String_split(const char* s, char sep, int* n);
 
 void String_freeArray(char** s);