New FP regression on Head over 2.7 release

[dp11]

int main () {
   int screendata[11];
   int *dp = screendata;
   int height = font->height;
   int step = 2;
   for (int i = 0; i < (height * step); i += step) {
      *dp++ = 0;
   }

  for (y = 0; y < height; y++) {
     if (screendata[y]) {
        break;
     }
  }

   return 0;
}

The above gives :

../FP23c.c:12:7: error: Uninitialized variable: screendata [uninitvar]
if (screendata[y]) {
^
../FP23c.c:7:22: note: Assuming condition is false
for (int i = 0; i < (height * step); i += step) {
^
../FP23c.c:12:7: note: Uninitialized variable: screendata
if (screendata[y]) {

Which I think is a new false positive. 2.7 didn't give a false positive

[CHR]

Thanks for reporting, I have created a ticket: https://trac.cppcheck.net/ticket/11006

[dp11]

Thanks for the fix of 11006.

Unfortunately my original case still fails before being cut down . New test case here
void f() { int a[11]; int *p = a; int height = 10; int step 1; for (int i = 0; i < (height * step); i += step) *p++ = 0; for (int i = 0; i < height; i++) if (a[i]) {} }

[CHR]

There is no FP with https://github.com/chrchr-github/cppcheck/commit/c71033548f57abee39faf9ee9776c653a1a5d4eb for

void f() {
    int a[11];
    int *p = a;
    int height = 10;
    int step = 1;
    for (int i = 0; i < (height * step); i += step)
        *p++ = 0;
    for (int i = 0; i < height; i++) 
        if (a[i]) {} 
}

[dp11]

Sorry something went wrong with cut and paste

void f(int step) {
        int a[11];
        int *p = a;
        int height = 10;
        for (int i = 0; i < (height * step); i += step)
                *p++ = 0;
        for (int i = 0; i < height; i++)
                if (a[i]) {}
}

This gives :

Checking ../FP6.c ...
../FP6.c:8:21: error: Uninitialized variable: a [uninitvar]
                if (a[i]) {}
                    ^
../FP6.c:5:27: note: Assuming condition is false
        for (int i = 0; i < (height * step); i += step)
                          ^
../FP6.c:8:21: note: Uninitialized variable: a
                if (a[i]) {}

[CHR]

I have reopened https://trac.cppcheck.net/ticket/11009

[Paul Fultz]

int step 1; is not valid C++.

[dp11]

Sorry thats a typo should be int step =1;