C Pointers Segfaults

Question

I'm working on a C project. The just of it is that we have a health vital reading program. I can add patients and add readings and remove patients. I have all the rest working, of which I'll link my code. I'm having a set fault that I've isolated in removePatient. I've tried gdb but for some reason it doesn't want to work with me today.

Here is the code in question:

void removePatient(int patientID) {
    int i, count;
    Chartptr patientsChart;
    Chartptr previousChart;
    Chartptr currentChart;
    CBuffptr healthTypeBuffer;
    CBuffptr allHealthTypeBuffers[MAXREADINGS];

    // if patient was found, remove the patient
    patientsChart = getChart(patientID);
    if (patientsChart != NULL) {
        healthTypeBuffer = patientsChart->buffer;

        if (healthTypeBuffer != NULL) {
            // gather all the heath type buffers
            count = 0;
            for (i = 0; i < MAXREADINGS || healthTypeBuffer != NULL; ++i) {
                allHealthTypeBuffers[i] = healthTypeBuffer;
                healthTypeBuffer = healthTypeBuffer->next;
                count++;
            }

            // free all the health type buffers
            for (i = 0; i < count; ++i) {
                free(allHealthTypeBuffers[i]);
            }
        }

        // find the chart before specified patient chart
        currentChart = patientList;
        while (currentChart != patientsChart) {
            previousChart = currentChart;
            currentChart = currentChart->next;
        }

        // reorganize list, then free patient chart
        previousChart->next = patientsChart->next;
        free(patientsChart);
    }
}

I believe I wrote the code to be fairly readable.

Here are some of the struct declarations that are used in the above code:

/* One health type reading: timestamp + actual value */
typedef struct{
    char timestamp[MAXTIME+1];
    int value;
}Element;

/* 
*   Health type readings: linked list of Circular buffers 
*/
typedef struct healthEntry* CBuffptr; /* pointer to a CircularBuffer */

typedef struct healthEntry{
    int type;              /* health data type (1-5) */
    int start;                 /* index of oldest reading */
    int end;               /* index of most current reading */
    Element reading[MAXREADINGS];  /* fixed array of readings */
    CBuffptr next;             /* pointer to next health type buffer */
}CircularBuffer;

/*
*   Patient's health chart: ID + linked list of  health type readings
*/
typedef struct chartEntry* Chartptr;   /* pointer to a Chart */

typedef struct chartEntry{
    int id;             /* patient ID */
    CBuffptr  buffer;       /* pointer to first health type buffer */
    Chartptr  next;         /* pointer to next patient */
}Chart;

/* global declaration for start of the patient chart linked list */
extern Chartptr patientList;

Answer 1

While I didn't look through most of your code, the following line seems suspicious to me:

for (i = 0; i < MAXREADINGS || healthTypeBuffer != NULL; ++i) {

I suspect that you want it to be:

for (i = 0; i < MAXREADINGS && healthTypeBuffer != NULL; ++i) {

There may be other issues too, but I'm pretty sure that the logic above at least calls for &&.