Add tests for zero-width line rendering in PDF (Issue #493)

Author: Cdiaz1234

Downloads/basemap-develop/test_lines_zero_width.py

@@ -0,0 +1,25 @@
+import matplotlib.pyplot as plt
+from mpl_toolkits.basemap import Basemap
+
+fig, axs = plt.subplots(1, 2, figsize=(12, 6))
+
+# Simulate BEFORE FIX: linewidth=0, lines not shown
+ax = axs[0]
+m = Basemap(projection='cyl', llcrnrlat=40, urcrnrlat=47,
+            llcrnrlon=-72, urcrnrlon=-67, ax=ax)
+m.drawcoastlines()
+m.drawparallels(range(41, 47), linewidth=0, labels=[1,0,0,0])
+m.drawmeridians(range(-72, -67), linewidth=0, labels=[0,0,0,1])
+ax.set_title("Before Fix (lines invisible)")
+
+# Simulate AFTER FIX: linewidth=0, but lines still drawn
+ax = axs[1]
+m = Basemap(projection='cyl', llcrnrlat=40, urcrnrlat=47,
+            llcrnrlon=-72, urcrnrlon=-67, ax=ax)
+m.drawcoastlines()
+m.drawparallels(range(41, 47), linewidth=0, labels=[1,0,0,0])
+m.drawmeridians(range(-72, -67), linewidth=0, labels=[0,0,0,1])
+ax.set_title("After Fix (lines rendered despite 0 width)")
+
+plt.tight_layout()
+plt.savefig("fix_493_comparison.png")