i.pca: Fix Resource Leak issues (#4664)

imagery/i.pca/main.c

@@ -314,6 +314,7 @@ static int calc_mu_cov(int *fds, double **covar, double *mu, double *stddev,
     DCELL **rowbuf = (DCELL **)G_malloc(bands * sizeof(DCELL *));
     double **sum2 = (double **)G_calloc(bands, sizeof(double *));
     double *sumsq, *sd, *sum;
+    int ret = 1;
 
     if (stddev) {
         sumsq = (double *)G_calloc(bands, sizeof(double));
@@ -358,8 +359,10 @@ static int calc_mu_cov(int *fds, double **covar, double *mu, double *stddev,
     }
     G_percent(1, 1, 1);
 
-    if (count < 2)
-        return 0;
+    if (count < 2) {
+        ret = 0;
+        goto free_exit;
+    }
 
     for (i = 0; i < bands; i++) {
         if (stddev) {
@@ -378,22 +381,21 @@ static int calc_mu_cov(int *fds, double **covar, double *mu, double *stddev,
             if (j != i)
                 covar[j][i] = covar[i][j];
         }
-
-        G_free(sum2[i]);
-        G_free(rowbuf[i]);
     }
     for (i = 0; i < bands; i++)
         mu[i] = sum[i] / count;
 
+free_exit:
+    for (i = 0; i < bands; i++) {
+        G_free(sum2[i]);
+        G_free(rowbuf[i]);
+    }
     G_free(rowbuf);
-
     G_free(sum2);
-    if (sd)
-        G_free(sd);
-    if (sumsq)
-        G_free(sumsq);
+    G_free(sd);
+    G_free(sumsq);
 
-    return 1;
+    return ret;
 }
 
 static int write_pca(double **eigmat, double *mu, double *stddev, int *inp_fd,
@@ -571,6 +573,8 @@ static int write_pca(double **eigmat, double *mu, double *stddev, int *inp_fd,
     G_free(min);
     G_free(max);
     G_free(old_range);
+    G_free(pcs);
+    G_free(out_fd);
 
     return 0;
 }